Via [url=https://blog.counter-strike.net/index.php/2021/09/35436/]the CS:GO blog[/url]:

[quote=Valve][OPERATION RIPTIDE]
– Introducing Operation Riptide, featuring new maps, new missions, and new ways to play your favorite game modes! Activate an Operation Riptide Pass and complete your missions to earn rewards including all new agents, weapon collections, stickers, and patches.

[GAME MODES]
Private Matchmaking Queues
— Generate a Queue Code and share it with your friends to create a private Premier match on Valve servers
— Or, select one of your Steam Groups and play a match exclusively with other members of that group

Short Competitive
— Added the option to select a preference for match duration in competitive Matchmaking: Short (MR 16), Long (MR 30), or No Preference.

Deathmatch
— Added the option to select Classic Deathmatch, Team Deathmatch (first team to 100 kills wins), and Free-for-all Deathmatch (all players are enemies).

Demolition
— Reduced max rounds to 10 and eliminated half-time team swap.
— Reduced round time
— Adjusted weapon progression

Arms Race
— Adjusted weapon progression
— Players now receive a health-shot after three kills

[GAMEPLAY]
– Grenades can now be dropped just like weapons.
– Vision after death reduced from 3.0s to 2.0s (vision by headshot reduced from 1.0s to 0.5s).
– Deagle
— Reduced body damage
– M4A1-S
— Increased body damage
– Dual Elites
— Reduced price to $300
– Riot Shield
— Added the Riot Shield heavy weapon to the buy menu, currently purchasable by CTs in Casual Hostage map groups.

[MAPS]
– County has been added to official matchmaking in Danger Zone game mode.
– Basalt and Insertion II have been added to official matchmaking in Competitive, Casual, and Deathmatch game modes.
– Ravine and Extraction have been added to official matchmaking in Wingman game mode.
– The following maps are no longer available in official matchmaking: Grind, Mocha, Pitstop, Calavera, Frostbite.

Dust2:
– Slight visibility tweak from T spawn through mid
– Improved visibility into B back site from upper tunnels

Inferno:
– Made gate at top of banana solid
– Revised 1v1 layout
– Minor bug fixes

Ancient:
– Increased size of plantable area in both bombsites
– Fixed bullet penetration on plywood surfaces
– Further optimizations
– Added 1v1 arenas[/quote]

Rumor has it:

- Size is an extreme ~2 GB - [b][i]data capped users should take action NOW![/i][/b]