I think its more probable to say that AWS didn't even know about this. As far as I can see, epik is just another AWS customer who spun up an instance and is hosting dns on that instance. I doubt AWS is watching customers at a level that would detect this. But, I'm also sure that AWS has since caught wind of this and is watching closely. I just checked, and both listed servers are returning an A record for parler, although its bogus info (probably meant as a place holder with low TTL so no one caches an nxdomain).
$ dig parler.com ns ...
parler.com.300INNSns4.epik.com. parler.com.300INNSns3.epik.com. ... ns3.epik.com.108450INA52.55.168.70
It's quite possible that Amazon is playing this *entirely* by the book, and the Parler crew haven't violated the terms of the nameserver hosting agreement so Amazon hasn't cut that off.