Strictly speaking, expert systems are AI as well, as in, an expert comes up with a bunch of if/else rules. So yes technically speaking even if they didn’t acquire the weights using ML and hand-coded them, it could still be called AI.

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_...