They basically transformed R* Social Club into a proper game launcher, nothing too extreme or shocking.
My GTAV copy is already there, at least now I have a nicer launcher for the game, even if I don't play it anymore.
It's useless to fight those launcher, just embrace them... and for RDR2, I will not exclude Steam for now, maybe they will sell the game on R*GL with some exclusives or more RDO money.
Still... even if RDR2 will be exclusive to this launcher, we are talking about 100% profit vs 70% profit on Steam, everyone here would do the same if in Rockstar shoes... cmon... be realistic.