That’s landing surprisingly late for a social platform.

Don't think many folks use the "Discussions" for actual discussions. Those mostly happen on the issues and PRs after all. So, there was probably never much disagreement or trolling on the capital-D Discussions, until presumably LLM spambots realized they can't get blocked there...

Oh, this is about discussions specifically? Were you able to block from issues before?

Well, it does say in the blog post:

extending the in-context blocking controls already available for issue and pull request comments.

So, I assume so. But yeah, terrible choice to refer to that as "discussion comments"...