Only if they add one.
No legislation has to include one. It is typically added to prevent outright revolt. Doesn't matter if you are talking about guns, taxes, or anything else, people get really testy if you try to take away what they already own. So what they typically do it write a 'grandfather' clause to allow you to keep what you have but prevent you from getting anything new. You are pissed. But the next generation has no clue what they are missing because they never had it so they don't realize what they lost.
Look for semi-auto registration soon after the next AWB. That would also likely include pump shotguns too.
Another reason they add them is to avoid takings issues. If they come take something from you, they have to reimburse you for it. With roughly 300 million guns in the country, they will never come take what we have because they don't want to pay market price for 300 million guns.