Has CSGO been renamed to CS2?

CS2 is a whole new game replacing CSGO

Csgo has not been renamed. Cs2 is a brand new game on a new engine that has replaced csgo on steam (seamlessly) as without the userbase would probably have stuck with csgo for at least the next year or two. If we look at the lifespan csgo had, the odds of another rebranding/renaming in the next 10 years is pretty unlikely. Csgo is still playable through the steam properties of cs2. Hope this still helps, if a bit late.