On one hand, limiting the number of posts that you can see on your social media site is insane obviously. It's definitely going to destroy the site. I guess we can welcome yet another group of people on the fediverse pretty soon.
On the other hand, 6000 posts is an awful lot of posts. Assuming that all you do all day is twitter, that's 300 per hour for an entire 18-hour day. If 6,000 post isn't enough for you, maybe he's doing you a favor.
That's if you're a weirdo who pays for Twitter. I barely use Twitter and was just scrolling through the Reddit and Twitter drama and was rate limited in like 30 minutes. To be fair, that's more than enough Twitter for me for the day personally, but yeah that's insane.
So, from what I've seen, it also counts comments under a tweet. So if you tap into a tweet, it automatically counts all of the comments as part of your limit. So, if you view a few popular posts, you're done for the day