In CSGO valve determines the 7 maps in the pool that will be played out at the major events and that are considered "Active Duty" in the in-game MM pool, and leagues tend to shift their map pools to align with valve as soon as they can. maps are usually rotated out based on community feedback, reworked, then go into the map pool while another is taken out for reworking.
Unfortunately going that route right now for tf2 would mean we would be playing turbine, swiftwater, and foundry.

personally i always enjoy having a new map in the season because its interesting to see different teams come up with different strats, with everyone copying each other when something good gets found. however there aren't really enough 'good' maps to have an actual rotation imo so unless you want to have 2 weeks of aids every season its not really worth it.

The pool of comp mappers is definitely not as big as it used to be (not too shocking, just like playerbase), though with the support of people like Lucrative working through new maps, we should definitely have plenty to choose from...

Let's think about this. What are the current maps in rotation?
ESEA (S30 pool):
cp_process
cp_granary_pro
cp_badlands
cp_gullywash
cp_snakewater
cp_sunshine
cp_metalworks
cp_propaganda
koth_product

ETF2L (S31 pool, S32 being voted on now):
cp_process
cp_granary_pro
cp_prolands
cp_gullywash
cp_snakewater
cp_sunshine
koth_product

ozfortress (S23 pool, S24 TBD last I've heard):
cp_process
cp_logjam
cp_prolands
cp_gullywash
cp_snakewater
cp_sunshine
koth_product

So, every league uses the following:
cp_process
cp_gullywash
cp_snakewater
cp_sunshine
cp_bad(pro)lands

With the outliers that are not used by every league being these (theoretically good enough for league play, maybe not universally liked / etc.):
cp_logjam
cp_propaganda
cp_metalworks
cp_granary_pro

There are also a few maps recently used in leagues that have dropped out that could be potentially subbed back in:
cp_reckoner
cp_cardinal

We also have the following up-and-coming maps that are looking really good from Lucrative's testing (please let me know if I've missed any!):
cp_kalinka
cp_alamosa
cp_bluff
cp_workflow
cp_mist
cp_craneway
koth_ordinance

I know that at least a few of those have seen recent cup play and are being updated relative to feedback - keep your eyes and mind open regarding them.

I think there's more than an ample pool of maps to try and switch one out here and there. No, the up and coming maps aren't going to play like process/snake/gully/sunshine right off the bat. I don't think they'll be entirely aids either, though. If you want the variety and you want more maps, there's options out there.

What do you mean? These maps have not been reworked, by valve or anyone, AFAIK.

This shouldn't be a goal. New maps should strive to make different experiences. For example, granary plays different than the maps you quoted, original badlands had a more punitive ammo management + last cap, etc.

What I really disliked during some lans were the pick/ban system, where a team could ban the same maps round after round and almost get away without playing a single time the map they did not practice. Being the best should mean being the best everywhere.

What about a "map wildcard"? A team could choose a map, and, a certain number of times during a season, force a fixture to happen on this map (unless the other team counter-wildcards you). You would then make the pool of wildcardable maps larger than the league pool to include whatever slightly sub-par maps, and let teams metagame each other.

in CSGO the mappool revolves around a single gamemode (defuse)
i think TF2 could benefit from that consistency of having 5cp only, a lot of people complain that koth maps are "just a dm fest" after all
eitherway, most players are against change and would rather play the same 3 maps over and over again :shrug:

KoTH is much more engaging as both a player and spectator, I think removing them would be a big mistake. If anything we need more good koth maps.

Yeah I think koth is really boring to play and watch, but everytime I mention that its clear that a lot of people are really enjoying it, so removing anything thats not 5cp isnt an option imo.

i thought people disliked koth more. the koth maps in the new map cup were garbage tho.
some actual great koth maps that people don't seem to know:
koth_bagel (autumn theme, best koth map of the past few years imo)
koth_whitecreek (alpine theme)
koth_cannery (asia theme)

I keep hearing all of these great things about koth maps, but:

I cannot get people to play koth_waterton. I didn't get terribly much feedback when ozfortress ran it in their midsummer cup #1, and for the most part the feedback that I have gotten is that it's fun to play. I'm more than willing to work on it, but it doesn't feel like the interest is really there.

all these maps have been tried and tested and share the same issues viaduct has already (maybe not cannery as much), lots of high ground for the defenders, easy to defend the point but harder to attack, forward holding is extremely strong.

Not saying these things are bad, it makes viaduct what it is but when it comes to new koth maps they should promote different gameplay and meta if more are going to be added. There are plenty in the works and undiscovered ones that fit this mold imo and I'm working to develop them over this season and possibly run a koth cup by the end of the season.

I disagree. By this logic why have sunshine/process/blands and not only one of the three? Even outside of those 3 several 5cp maps share the same features and flaws, and it's not a reason for not playing them. What does logjam change on the standard 5cp formula for example?

Did you do waterton in one of your maptest pugs? I've never seen/played it.

ya this isn't even remotely the same argument considering 1) those maps are not even similar and 2) Koth maps are literally 1/3 of the size of a 5cp and they are very easily made the same (and yes, those koth maps listed are basically the exact same format if you actually look them over and play on them)

I am not describing "features" of the maps being the same, every map has influence from other maps in one way or another. what Im describing is all those koth maps share the same structure (high ground middle point, easier to defend than to attack, oppressive forward hold) and there are a lot of koth maps that don't share this structure of play. This does happen in some of the 5cp maps in the rotation currently, but I wouldn't agree that any 5cp map in the rotation currently shares an almost completely identical structure like bagel, whitecreek and even isla (I think ordinance is the only map to break this trend, personally) do in comparison to viaduct.

those maps aren't similar?
easy last to turtle into with offclasses
2nd point has highground over last lobby giving defenders a very easy time
sightlines from 2nd to last lobby impossible to deny (tbf sunshine is less flawed on this than say, snake)
highground on mid for mid defenders

To me this is is clearly maps sharing the same structure. And it's not a problem. People enjoy playing variations of the same structure. So I don't see the problem in having 2 maps using the viaduct formula.

Now in EU we dont play coalplant. I believe it's significantly different than viaduct, so what were the reasons of stopping it in esea?