I think people’s issue with OW2 replacing OW wasn’t the inability to get into the old game, it was the irrevocable changes. Like, I think there is more issue with the changes to free loot crates and characters than “but my OW1!”
From my understanding, CS2 doesn’t have glaring changes like this.
However, to your point for new games replacing old ones - I’m conflicted. On one hand, there’s little point booting up Star Wars Battlefront 1 by EA, but it would definitely have been shitty if EA had replaced it with BF2.
But as someone else mentioned, you can also still boot into CS:GO. So if the issue is wanting to play with friends, that should still be possible. It comes down to how it’s done I guess.
Thinking about it, it only seems like some IP’s can really do this anyway. Battlefield probably can’t, unless they decide to stop using themes for the games. Battlefield 1 just can’t exist in Battlefield 5. Call of Duty could probably find a way to accomplish it though.