Typical chess programs are specifically designed to play chess. A lot of human knowledge about chess is hard-coded in these programs. These programs are therefore not AI. They play chess and only chess. Bing AI on the other hand was never designed to play chess. It was merely designed to predict the next word in a text, a task that is quite different from chess. If such a program can play chess, that's much closer to what one might call AI, because it learned the rules of chess and chess strategy and tactics on its own. However, let's not get carried away, GPT models do play decent opening moves, but then quickly start predicting illegal moves. What they're doing is best described of having memorized common opening moves and they don't really have any solid understanding of the game.