Looking through the repo to find the source of your screenshot, I've noticed that they only had that address in their readme for 6 weeks or so:
Introduced Aug 26:
https://github.com/zedeus/nitter/commit/f75bf5872e36a255a9765114ec0eb2a0394bef1f
Removed Oct 9:
https://github.com/zedeus/nitter/commit/145ca9eb68d195a74598ae39a4d6da002b252c38
I wonder whether this wasn't any sort of ideological alignment, but just "oh no, we got a cease & desist, help!" after which poa.st was like "we can help you protect free speech!!1!" and zedeus had no idea who they were 🤔