Will we be allowed to discuss Hangman/Wheel of Fortune puzzles?
If the author of a question has to come back and say "Yes, you were correct, but not any of you other three. That one person answered the word I was thinking!", then no, such questions are not on-topic. See also my answer on: Is asking about picture puzzle on topic?
On the other hand, I would argue that asking questions about how to solve hangman puzzles, such as what algorithms or methods to use to choose the most likely letters used in a word, are on-topic.
Why not? It is a puzzle. We shouldn't and can't limit the scope too much and expect to gather a suitable community. Please note though that questions about the puzzle would be much more appreciated than "what could _ _ _ x _ be?"