The username himself (Cryptocrit) has deleted all the posts in his profile. And only this behaviour of deleting the Posts indicated that he was deliberately using AI to post in the forum.
Is it possible to delete posts and activities from an account by the account user/owner?
This Cryptocrit is trying to cover every step he/she takes, and that is why he/she is providing links to a website of the post he/she is making here in the forum. This is a way of generating traffic to that website (whether it is his own or not).
Yes there are some boards that owner can delete his posts while he can't delete some boards except with the help of the moderator of the board. But in this case, as you can see from other comments, he didn't delete the posts but because of the ban, and as the account got nuked, the posts were hidden.