... and it’s applied (FWIW, will the onebox in my post above change to the new name, making it sound like I am mad?).
I think that the position put forth in the old annotation to Hesperion was somewhat defensible: keep the old name, until the new name has gained enough notoriety. I don’t share this opinion, though, especially not in the extreme interpretation ("let’s wait until there are more albums credited to the new name than to the old one"). For artists that have a long history already, this just would not do.
The main motivation would be to make artists easy to find under the name most familiar to people, but aliases are the solution for that.