And "release all claims" is precisely why I didn't sign for a paltry two weeks severance at one ex-employer. Don't speak ill of them? Fine, whatever, I'm content to never speak of you again, positive or negative. But let you off the hook for when it occurs to me weeks later that you have illegal hiring/firing patterns? Umm, no, not for a measly few grand. (And though a solid case could have been made for unlawful termination, I left it be because I was a month from quitting anyway.)

Right. They need the signature to get free of any wrongful termination suits. Though, the non-disparagement clause pretty much ties in with that, I suppose.