That's up to you. If you want them in your collection then keep them. If they end up changing names, returning them to the casino either now, or when they change names is irrelevant. The casino will reimburse you face value for the chip no matter the name on the front door. But remember, once you turn them in, you may not get them back unless you are willing to purchase them for a slightly higher price from a chip dealer.

All gaming jurisdictions, like your mileage, may vary...