You were made "redundant" 2 years ago. You don't owe your past employer anything and you sure as hell don't owe anything to a company trying to minimize their

You were made "redundant" 2 years ago. You don't owe your past employer anything and you sure as hell don't owe anything to a company trying to minimize their headache in the future if something with their deal with your past employer has a hole in it. I'd just wash your hands of the whole thing and ignore it. If they come back with some $$ then perhaps revisit. Life is to short to be wasted being a 3rd wheel.