I see this development in terminology as a departure from the actual revelation God has given to us. It's a theology based on creative speculation and imagination, grabbing a text from over there and combining it with something else that isn't even talking about the same thing. If we're talking about what antichrist means, how about we stick to what John said in 1 and 2 John (the only places the term is used).

Assuming the false prophet is THE capital A Antichrist is a huuuuuuge leap with zero textual basis.