Via [url=http://blog.counter-strike.net/index.php/2016/02/13678/]the CS:GO blog[/url]:

[quote=Valve][ MISC ]
– Fixed a case where Gemini campaign mission could not get checked off in the campaign journal even when the mission was active for the player at the time of completion.
– Added engine support for up to 4096 model precache table entries.
– cl_timeout setting is now capped at 30 seconds.
– Fixed weapon_fire event for the Medi-Shot having the incorrect “weapon” sent.
– Added missing tagrenade_detonate event.
– Fixed missing alphas to resolve un-skinned areas on the following weapons: USP-S | Royal Blue, P90 | Desert Warfare, UMP-45 | Corporal, SCAR-20 | Cyrex
– Improved vert count on SCAR-20 scope
[ UI ]
– Fixed not being able to select the 5th slot when you have a bomb and medi-shot equipped.
– Fixed not being able to cycle through items in the 5th slot if you had more than 1.
– Fixed inventory UI hiding when preforming actions on items (like applying stickers) while in the lobby.
– Fixed lobby displaying incorrect player data when searching solo and using the inventory.
– Fixed sticker model panel overlapping quit lobby dialog and other dialogs.
[ GSLT ]
– User accounts will also receive a temporary cooldown when their Game Server Login Token gets banned.[/quote]

Rumor has it:

- The GSLT bit only applies to server operators, for regular players it doesn't mean much

- Some Wildfire lore elements were altered: https://github.com/SteamDatabase/GameTracking/commit/6b9cf434f046e3456f643ffa40d5d30ecfd65f15

- Size is ~85 MB