What makes you say that? I'm genuinely curious. I'm the named inventor on a few of patents for a previous employer that were all granted after I left. It never occurred to me that they would continue to need my services (nor have they).

BTW have you asked your previous employer about the situation? My guess is that @smoyer's situation is fairly rare and the company will likely consider it a perk rather than an entitlement. It's not clear there would be any harm in asking though.