sort of doubt FN has much to do with anything sold by PSA due to the DOD's restrictive policy on selling GI contract parts to the public.
from what i have seen of PSA uppers they look like a mix of LAR/CMT made stuff of which there is absolutely nothing wrong with.
IF the BCG's were FN or colt they would have a de-mill mark. so far i haven't seen one with that de-branding mark. i do suspect their barrels are made of the correct mall ninja steel, i do have suspicions of who made them but i'll go no further. i don't think their FN though. just look north--LOL.
i consider the PSA uppers to be very good and probably the best out there for what they cost.
keep in mind i have only seen a couple of them--so YMMV.