The only head-scratcher I'm seeing right now is the producers seemingly focusing exclusively on former J! and WWTBAM contestants for their talent pool. The whole gimmick of the original "Chase" (UK) is finding the "average Joes" that can take down the super-quizzers. One episode featuring, say, four of Ken Jennings' J! victims over the years might be fun, but going to the wall multiple times with that gimmick will be tiring.
As a member of the trivia community, I’m a little conflicted. On one hand, it’s nice to see people I’ve played against get shots on these quiz shows, but to your point, I feel like the highest end shows have become a rotation of familiar faces on shows where they want “smart people”. I saw it on MasterMinds/Best Ever, and even more so on 500 Questions.
I think you’ll see it less in the coming years though. Millionaire’s focusing on community heroes this upcoming cycle, Master Minds can’t be running too much longer based on the life cycles of GSN originals, and Alex hinted last summer that the GOAT would be the last super tournament for a while.