That has nothing to do with this. A work extension MUST be cancelled, even if you just let it run out, or leave without a re-entry permit, you still MUST cancel it. If you don't cancel it, you likely cannot get a new long-term visa or new long-term extension until you do so, and will also be fined 500 baht per day for failing to do so. There are also land borders that won't even let you leave Thailand if you haven't cancelled your work extension and don't have a re-entry permit.
Same goes for education extensions and volunteer extensions.