Theoretically, in practice ISPs have been largely been handing out PDs and calling it a day (for consumers at least). This means you get many networks worth of v6 but they won't statically assign those many networks of v6 to you. That said they don't actively try to make them change and they aren't under pressure to use every last IP like IPv4 and for many carriers it's unlikely you'll ever have your v6 PD assignments change after a boot (ATT fiber is a good example). Of course if you do you're usually just shit out of luck as extremely few carriers provide the option to customers on v6 for whatever reasoning.