got a severance package
There are no gurantees that you would be offered another severance package unless one is required by some sort of employment contract, CBA, or required by law. That said, why are you worried? If they bridge your service and then lay you off in another two years, if they pay you another severance then good for you. If they don't, nothing ventured.
I haven't signed, nor was given anything to read concerning this
What are they asking you to sign? Personally I would NOT bring up any previous severance package or the possibility of getting laid off in the future. If you want to return to work, go for it. If not, don't.
"Never argue with stupid people, they will drag you down to their level and then beat you with experience." - Mark Twain