The patch isn't Snorlax-sized, but definitely takes big damage from Grass Knot.
http://www.nintendoworldreport.com/news/62083/pokemon-scarlet-and-violet-will-require-patch-for-online-play
The online features of Pokemon Scarlet and Violet will not be ready until launch day.
A day one patch (to version 1.0.1) will be required in order to access all of the game's online features, according to the Pokemon Company. The patches require at least 1GB of space per game to download.
Advertised features, including multiplayer Tera Raids, online exploration, and the Mystery Gift function that unlocks Flying Pikachu, are all tied to the patch.