Anecdotally, I have seen the h1b under leveling happen multiple times. But not sure it’s common enough to skew the data but it does stand out when it happens because you have a great engineer with 10 years experience and you find out they are an SDE1. For every one of those there are probably 10 that are correctly leveled or over leveled.
I know nothing of this world but I’m curious what incentive do you have to give back equity that is already yours? Wouldn’t a company just buy it back in some way or dilute you once they get more investment?