Are atheists who aren’t materialists truly atheists?

No. I am not an atheist. As you should well know, because it’s come up before.

It’s strange that in most discussions people accept that individuals get to describe their own position, but when it comes to religion some people feel entitled to override those descriptions (see: “Mormons aren’t really Christian”).

You don’t have to agree with my terminology, but repeatedly telling me what I “really” am after I’ve explained my position is more about imposing your framework than understanding mine.

See above.