Yes, they are fine
While slower twists appear on most varmint rifles, it is usually because most varmint hunters will never shoot over 55gr bullets. I have heard from credible sources, (Bill Alexander, and the owner of JT Custom Rifles) who know the AR platform well, that you cannot “over stabilize” a bullet, and that light bullets spontaneously exploding in mid air from being spun to fast is largely a myth. That said, I cannot give you a good answer as to why too much spin could be harmful.
Your AR will do fine with light HP’s and even with polymer tipped rounds. I shot a raccoon with a 45gr Federal varmint round from my bushy 20” barrel at about 60 yards, and it left a hole that you could drive a Mack Truck through. Talk about “explosive performance”. At 200 yards they will work like they are supposed to, and perform reliably.