The villagers never mention him at all, he doesn't exist in my game as a character.
Dizzie was kind enough to donate her Wolfgang to science. I invited him to move into my town and he accepted. Next day I got a letter saying he was not going to move in. It did not trigger the invisible Wolfgang house to appear.
I want to publicly thank Dizzie for dedicating her time and Wolfgang at the slim chance it might fix my game. I really, really appreciate it. Sadly it did not work though.

Looks like I am completely out of options other than restarting my game, which I refuse to do! Instead I will dedicate my town to the invisible house
It has also been several days and none of my villagers have asked/talked about moving. By now usually one would want to move. I am starting to think that no one will move out either!