It is 100% valid to label an algorithm that plays tic-tac-toe as "AI"

Much of the early AI research was spent on developing various algorithms that could play board games.

Didn't even need computers, one early AI was MENACE [1], a set of 304 matchboxes which could learn how to play noughts and crosses.

[1] https://en.wikipedia.org/wiki/Matchbox_Educable_Noughts_and_...

Yup this is exactly my point, in the 80s there were plenty of “AI” companies and “fuzzy logic” was the buzzword of the day.