[bigwinnerx]

Does seem terminology normally associated with the younger gen of card collectors has crept into pre-war a bit.

Probably started with a smart collector knowing they could bring in younger collectors by using phrasing/language such as "rare" (even if it isn't), "1/1", "low pop", "highest graded", etc, kinda mirrors the modern collector mindset of ignoring base and looking for refractors and inserts. So, price runs could certainly be from this new wave of younger/more naive (of which I'd still count myself a bit) collectors coming into the market.