I was thinking more on the lines of generic FAQs being answered until a member of staff logs on and can provide better support. Though you’re right, it would try to offer what it believes is solid advice but it won’t be able to fully answer members questions.Support? The only context I'd ever want AI bots is to direct people to existing content; it's more likely to give them bad advice confidently than it is to give them good advice. (Not that it can't give good advice, because it can, but it doesn't have any understanding, it'll just be looking for words that match.)
Roleplaying... I might try that in a private board when my next site gets set up. I rather suspect it'll die on not having enough material to work with and leaving the other person not even remotely enough material to do anything with. But we shall see. (I also think it'll die on not having access to any of the lore.)