Pretty much. More like “was their appearance on H2 during those weeks the only time they were on a game show panel”.
I don’t think the total is very many, if any, but I’m curious.
The only one I was thinking of was Jim Lange, but apparently he also did one of the primetime Feud specials in the 1980s in addition to participating in the Card Sharks game show host tournament which I forgot he was a part of.
Yeah, Jim Lange was the only one I thought would correctly answer your question, but the Feud host special captured him and several others, like Bob Eubanks. Eubanks also did Liar's Club. Wink and Chuck Woolery were on Tattle Tales. Wink was also on Password Plus and Card Sharks. Peter Marshall did Baffle and The Last Word.
Game Show Week II skewed more towards regular panelists (Betty, Joanne, etc.) than hosts. Tom Kennedy was on Part Deux, and did lots of game shows as a guest. Monty Hall did Tattletales and Password.
So the ultimate answer is no, it was not the only game show appearance for anybody in the squares for those weeks.
-Jason