Weeeeell... Ann, while my favorite, had the slower progression in the original too, if memory serves. Furthermore, Ann has a boyfriend, storywise, so that slows things.I get the impression that Ann is not Aleksey’s favourite character
the Ann updates are very small whereas the other characters stories are progressing more
Game-wise, I think she is the most-affected by the different paths, so her updates have to cover different routes while for other characters, things are less diverse.