Ever since Marvel the End I consider all of Starlin's infinity stories to be in an alternate universe that I call the Starlin-verse.
Marvel The End had the premise that heroes would no longer come back from the dead after Thanos fixed things, however heroes and villains still return.
His latest trilogy had a merging of two universe and an overwrite of Adam Warlock. The alternate version becomes the new Living Tribunal and restores the original Adam Warlock but the main MU doesn't seem to acknowledge Warlock-Tribunal's existence.
So let Starlin keep his private universe and write Thanos.
I'd rather see him focus on the Dreadstar TV series project, personally.
He is doing a Dreadstar program!!?