A company which is even moderately "OK" at IT will already have the means to instantly lock and securely wipe devices of any employee at a moments notice. Doing this during a RIF is a hell of a lot better than making the mail room deal with a bunch of filthy laptops.
If they sell to (ex-)employees they sell to consumers. This then includes consumer warranties etc.
However what large companies do is to get an agreement with a refurbishing company, which will collect and refurbish them and and pay the corporation some share.
This works in some mix calculation - the well treated machines can be sold well, some machines can be used to reuse some parts and some machines are nothing but cost for disposal.
If you scrap a laptop you get a nice, auditable, chain of custody from the end user to the company that will certify it's been destroyed. If you sell someone their old laptop you need to ensure that it's actually been wiped, not just "I copied my files over and started using the new one". I've seen a few IT departments be not great at "Sam got their new laptop two weeks ago, someone should follow up now to see if the wipe on the old one happened".
One choice won't get you fired, the other might save you a bit of cash.
A large bunch of big companies, including some of the biggest on the planet don't even sell past-end-of-life laptops to their current employees.
Let that sink in. They're not even willing to <<sell>> old laptops, they would rather scrap them and contribute to pollution and overall waste.