Of course there are power dynamics at play here - more or less of them depending on how crappy vs decent the company is. However, I don't see any power play in

Of course there are power dynamics at play here - more or less of them depending on how crappy vs decent the company is. However, I don't see any power play in the words themselves. An employee being fired and an employee resigning are different concepts, and different concepts get different words. You could read something into the word "firing". But don't most companies avoid that word in any case, in favor of "letting go" or "dismissal"?