It is not an "invented' prefix.
It is a perfectly real and historical prefix that has been hijacked.
Well, its use in English, as they are using it now, certainly is a recent invention. It’s not as if “cis” has always been a commonly accepted prefix in English and people just didn’t know about it until the whole Bruce Gender fiasco. Academics dug it up and dusted it off specifically for the purpose of obfuscation.