Google is your friend, too, friend.
But I’ll give this one moment.
Cis is a prefix that means, “on the side of” It has been used to describe gender since as early as 1914 (German) predating you or me, presumably.
Trans is a prefix that means “across, beyond, or on the other side of.”
I couldn’t care less if you “like” the term, it is not new, nor is it controversial in reality.
Gender alignment is not the “normal” it is just more COMMON. It is in no way a “default” unless your mind needs that. Milne doesn’t.
Everyone has a gender identity, even if that is neutral or fluid, or they choose to be obtuse about it.
So long as trans people are sorted and othered by the term “trans” - it is wholly appropriate to denote Cis as well. Whether you think so or not.
Perhaps there will always be things you choose not to understand or “allow” inside that brain. You certainly have that right.

Trans is not a “condition,” and our only suffering comes from folks who intentionally demean and question our existence as somehow suspect.
Good day.