Have there been any other states that passed a mag capacity limit that didn't have a grandfather clause?
yes. The most recent one was New Jersey. They passed a 15 round limit in 1990 with no grandfather clause. A couple of years ago, they reduced it to 10 and the federal courts didn’t care.
HawaiI passed a 10 round limit for pistols back in 1994 with no grandfathering provision.
California’s ballot initiative back around 2016 retroactively banned 10+ round mags. The 9th circuit reversed it to have to court of appeals reverse them to allow the law to stand.
Courts will uphold this like the 3rd circuit did for NJ when they lowered it to 10 rounds. The useless Republican appointed “federalist society” judges and justices are worthless.