I think this is a holdover from before, where the request was to not use AI before the leaderboard is filled up. If you are stuck and have to ask a friend for help, you are not going to make the (global) leaderboard anyway.
In practice, nothing prevents you from using AI to solve the problems anyway.
The subreddit also had a policy of not unlocking the megathread until the leaderboard was filled up. So any hints there will also be too late for the making the global leaderboard.
And the old About noted what you just said about there being nothing preventing someone from using AI:
> If you want to use AI to help you solve puzzles, I can't really stop you, but I feel like it's harder to get better at programming if you ask an AI to do the programming for you.