It's, like, using active voice. Like it's a thing the employees are actively, purposefully, doing or perpetrating. Of course it doesn't actually unambiguously say "and they've fully consciously decided they would like to no longer work to", but it's definitely language that's designed to, however ineffectively, not draw attention to the blatant fact that the company has chosen to fire people.

If someone is carried out of a bar, would it be accurate to say they left the bar? Sure, but not of their own accord.

I guess when immigrants are given the boot on the backside by a nation state, they are also "leaving".

And yet it's an active verb, not a passive.