this is
1) a bit misleading to call them "nones"... what about the actual nones who simply don't believe anything at all?
2) disappointing and fundamentally different from eg northern europe where it's fine and common to simply not believe in anything at all, without feeling any huge need to "correct" that
atheist noun a person who disbelieves or lacks belief in the existence of God or gods.
We atheists believe things. We just don't believe in gods.
You can find spiritual atheists and superstitious atheists and atheists who are flat earthers. All manner of nonsense. But they don't believe in gods.
Some people use "nihilism" to mean belief in nothing, but there are self-proclaimed nihilists who are offended at that.
antitheist
a person opposed to belief in god or gods.
In this day and age many atheists feel the need to be antitheist.