Uhh... I'm pretty sure the conch wasn't the reason that they won that point?
Lanksy gets a solo uber to try and force the other team to multi, doesn't really work out and it looks like their goal was simply to get an uber exchange to happen so that neither team has uber.
The important point here is that on last pushes, often it's not the uber fight that determines if you cap it or not but the post-uber fight.
Gully is unique in that it's the only map where you can run scouts to the point without having to uber them since there is a river route that takes you under.
On a standard map to run a scout onto the point the scout either has to sacrifice himself or get a flash of the uber, and once you're on point the enemy combo can just use their uber to block the point, buying the 3 or so seconds needed for the demo to lay stickies on the point again (he would have det them to kill the initial baiting player) or have a soldier/heavy drop down and sit on the point. Also, in order to bait the point (or edging the point, walking close to the capture zone and then backing off so you don't die to the stickies) you have to be basically in the middle of last and everyone can shoot you (think badlands last) but in gully you are in the relative safety of the river area which is enclosed.
By having an uber exchange at shutter door and then doing a repush with scouts baiting point from lower you force the enemy team to commit bodies onto the point to block once the demos det his stickies. Once you have the defending team committing bodies to block the point all you have to do is keep your demo alive and buffed to spam the point and collapse on the enemy team.
This is a textbook point-bait and collapse that followed a uber cycle. The conch played no part.
The conch's speed boost would be negligble when travelling such a short distance (from river to cap point).
Also the reason iT won this point was more about lit's incompetence rather than iT's play or iT's use of the conch.
Firstly, lit's medic wasn't pressured at all, Lansky was doing shit all with the uber, in fact, you can see most of the uber gets wasted back in lobby (since they weren't trying to do anything with the uber, they just wanted to see the other team uber as well). Lit's medic could have easily held that uber charge (even let the pyro die, trading a pyro for them having to use uber and you don't is a big win and a good trade, don't use your uber to save your pyro if you as a medic can survive). Now iT has used uber and Lit hasn't, good luck trying to push with that. Lit's medic should have kept the healing beam on the pyro and as Lansky gets walked in with the uber the medic should have run away to hide behind the heavy, let the pyro die and waste 50% of the uber, now Lansky has to make his way to the back of the point and take down a heavy to <100HP to force the pop in 4 seconds, an impossible task.
Most likely lit's medic was playing it safe, MOST of the time when the enemy medic pops it's almost a free pop for you, since the worst that can happen is that you get even ubers again on the next uber cycle but if you don't pop the worst that can happen is that you drop it and they get to fight uber v non-uber. I watched the cast and lit's medic was popping every time Lansky ubered in, even if Lansky didn't do anything with the uber. Even the casters were saying the pops were too conservative.
Secondly, once the point started to be baited lit did nothing, they just let them cap. A heavy should never be alive at the end of a last defence, all his health should be used up to force the enemy team to use their ammo on shooting a 450 russian. The fact that the heavy wasn't on the point, was still alive meant that it was a pointless play to run the heavy, you didn't maximise his health advantage over other classes.