How is a mockup a viable product?
Very bizarre twist of words, but that's what it is.
Sure. Just don't pretend it's something that it isn't.
> Wether you call it "MVP" or not is purely semantic
Well, no. It's not the correct use of the term. Let's be dramatic and look at the worst case: deliberately misusing a term-of-art like 'MVP' may be tantamount to misleading investors and clients.