yeah, but its a common thing that PC players usually don't like other launchers, even games that are available day one on game pass tend to hit higher numbers on steam, for example, Starfield on launch hit 300K CCU on steam and it was "free" for gamepass users.
so using SteamDB as a metric of how well the gaming in doing on PC isnt really that crazy imo, sure, like
Topher
said, a lot o ppl ( he included ) ll be playing this though Ubi+ but these aren't sold copies and they ll tank the game revenue somehow.
at the and of the day you play where you want, but i think ( and thats is my opinion ) for a dev big as Ubisoft and a IP big as AC 25K on release is really low.