This is certainly by design.
The client has no way of knowing if the topic you were looking is public or not, we could carry a lot of logic here to allow for this, but the way I see it being logged out is a super rare condition and in such a condition it should be thought as a “reset button”.
A “reset button” should take you back to home.
I guess I support changing the label here but I am not sure what we would call it “Refresh to Home Page” is just too long.