While I'm sure this is being used as a "gentler" term for being fired (and I'm sure perception will catch up as it did for terms like "opportunity"), I can think of one case where this is different from being fired. I've seen it happen at a couple of companies where someone high-ranking suddenly "retired" or "resigned" and it was obvious that it was a face-saving way to get them out the door. I could see the word "resignated" being used for these face-saving faux-resignation/retirements.
The appearance of a sudden desire to embrace, family, fishing, early retirement, etc is usually better for all parties.