I'll Try again:

"How are YOU defining what is or is not BLUES?"

    "The same way blues fans generally do today" Oh really?

I assume that you have documentary evidence and another long list consisting of the names of blues fans that agree with you or who care.

Early New Orleans jazz musicians lived in a musical melting pot and would hear and be interested in many musical styles including blues. If blues was popular among the paying customers then they would be very, very interested. 12 bars, 16 bars, 8 bars, completely irrelevant likewise who "invented" it.