It seems to me that AI's current advantage shows up most in writing tasks that involve a lot of effort, but not at incredible individual insights. To some extent, a great tweet is all insight. For this reason, it may be one of the hardest things for AI to beat humans at.
Because of its speed, AI's advantage over humans on long-form written content (papers, articles, literature reviews) seems larger than its advantage on short-form content (tweets, short Substack posts). For this reason, I'd expect the "best" tweets to stay human longer.