In some cases, the new term is just a euphemism, and it means exactly the same thing. Like how "homeless" turned into "unhoused". There's no difference in meaning. It's just meant to sound nicer.

In my book, it's the same for "used" and "pre-owned". It never occurred to me that anyone would think a "pre-owned" vehicle automatically came with a warranty. It was just a nicer way of saying that you weren't the first owner, without using the word "used" (which evokes "used up"). Also, I think sketchy used car lots sell what they call "pre-owned" vehicles, even though they don't provide certification and warranties (at least not ones you can count on, since they could just disappear overnight).