When confirming people recognition, there is a series of confirmed faces and then below it more faces with a question, "Is this ____?" Most of the pictures are correct, but when I highlight a couple that are not, the "rename" button at the bottom lights up, implying that I can rename just those two and then continue confirming the other faces. But that's not what happens - it incorrectly renames (in my case) over 700 other faces to be the name I entered!
It sounds like you may have hit the Not this Person command (which is easy to do) when selecting the people you wanted to rename. If this occurred, the photos will be put in new stacks in the UnNamed People room.
Greg S, Thanks for your reply. I'm pretty sure I hit "Add name", not "Not this person" because I got a dialog asking what name I wanted to use. My complaint is that after I entered the name (that was intended for only the two selected faces out of the hundreds of faces listed), all of the other faces disappeared. I did find a stack with about 200 of them in the unnamed people room.