I saw this done at a former employer, and it had a nasty side to it. The employer said, "You can volunteer for severance, but we chose the time that you leave, and you can still be fired for cause between now and then, and we reserve the right to change our mind and deny your request".
A lot of people took the deal, and thus were identified and known to the company as "ones that didn't want to be here". Sure, a lot of people ended up getting a package many months later, but those months were not fun. A lot of people volunteered for the package and still quit voluntarily (or got fired "for some cause") and never got a dime.
Companies are crooked. WF is no exception. Indeed, WF is quite skilled at it.