Good catch. The account looks like it was purchased but it has been owned by a Russian since the beginning so its difficult to say for sure. Their post history is chock full of AI posts, however. Here's a few more.
The account still belongs to a Russian user. Most likely, he writes in Russian but uses an AI translator to translate into English, which is why his posts are recognized as written by an AI. His writing style is similar in both languages. Perhaps he should be invited to this thread so that he can clarify the