Okay, I'll tell you what I assumed when you said that.
You think all catgender people are the gender they were assigned at birth. Male to cat? That's a man. Female to cat? That's a woman.
This is a logical deduction. You said catgender people aren't queer. That means they can't be trans, and can't be nonbinary. This is the consequence of you saying that.
And I am begging you to take it back and allow catgender people to identify as nonbinary.
Otherkin showed up 100,000 years ago when modern homo sapiens developed. I seriously doubt you can isolate a single decade of queer acceptance so long ago.
You're just engaging in the time honoured trope of calling something new because you, personally, didn't know about it when you were young, and now you think learning about new kinds of people is scary. People said it about gay. They said it about bi. They said it about trans.