I'm at a v50ish firm and of course there are regular comings and goings. However, I've received 5 last day announcement emails from 3rd and 4th year associates so far this week and know of another leaving Friday. I by no means get cc'd by every departing associate. I can't recall getting more than one in a week.
As a fellow 4th year, I guess I'm just glad I'm not one of them.
Something's afoot, and it smells like stealth layoffs.