In the "private discussions" page, clicking the 3 dots stack on the right of a discussion and selecting "leave this private discussion" throws me into the "all discussions" page after unsubscribing. It would be nicer, if after unsubscribing a private discussion, one would still be on the "private discussions" page near the point where the action took place.
Similarly leaving a private discussion from deep in the "all discussions" page throws the focus back at the top of that page. That's annoying too.
So in both cases remembering where the action was performed and staying close to that point would be nicer.
Or let's phrase it that way: Don't confuse users without a good reason.