Earlier quoted context omitted.
I'm not going to lie; that type of thing -- resigning right after getting promoted -- seems like something from some alternate reality fantasy world.
It is entirely possible they weren't planning on getting promoted. I was due for a performance review about a week before I handed my notice in at my old job. The review didn't happen because my boss was incapable of communicating with his employees and actually scheduling appointments with them, but had it happened, I was fully prepared to push for a payrise, even though it would only be a couple of dollars an hour,…
Too late though. :)