yes but also sometimes just knowing a persons identity can infringe on their privacy

I would say anonymity is an aspect of privacy, one you sometimes but not always need.

e.g. I would say leaking who was present at a anonymous self help group isn't just breaking anonymity but also infringing on privacy

I didn't say that identity wasn't privacy.

I said that the post I responded to was conflating two different types of privacy.

Who said things is different to what was said.

Bob and Alice spoke about something, is not the same as Anon to Anon "The government is listening".

One is the message and one is metadata. They are protected in different ways and leaked in different ways. Mixing the two means that you will probably not get the protection that you desire.

Just because you don't use your name doesn't make the service anonymous. Pseudo anonymous is still in the privacy bucket because there's still likely (given websites today) personal information associated with your account. True anonymity could be achieved, but it'd be difficult to maintain.