The person behind nitter.poast.org, as seen here, has been outed as some reactionary former dev of 4chan: https://accollective.noblogs.org/post/2021/06/18/admin-of-poa-st-anime-graf-mays-revealed-daniel-stevens-of-ontario-canada/ (CW: racial slurs)
He is also the admin of Poast, which is a reactionary instance on the Fediverse, reactionary to the point where even MSM had articles about it.
Needless to say, I'm going to use another Nitter instance (nitter.esmailelbob.xyz) and I would encourage others to do the same. Here's a list of Nitter instances: https://status.d420.de/ in case nitter.esmailelbob.xyz turns out to suck as well.
Edit: Damn, it turns out esmailelbob sucks as well lol
Twitter prevented the creation of guest instances, which was how nitter was working. Nitter could still be used by routing the traffic through actual accounts but no one wanted to deal with the hassle of that, especially when the boer could just shut it down.