Canon is a mutable thing, continuity-wise. Any long-running canon will retcon or ignore inconvenient ideas or mistakes from its past, but the broad strokes of the series will still be assumed to have happened.
And it's as true of any other long-runner (TV, movies, literature, comic books...) as it is with Star Trek.
I do think it's important to have some
over-arching structure to a franchise. But I reckon anything beyond that is definitely mutable. The best kind of canon is one that the individual comes upon for themselves.