I don't see why the P.108 would be a lower priority than the Meteor. The Italian air force is poorly represented in this game. On the other hand the British, Americans, and Germans are highly represented when looking at their percentage on the plane set.
I agree the Italian set needs to be added to, but by the aircraft they actually fought the war with, not aircraft that represent a tiny fraction of their forces at the absolute tail end of their participation. If you'd said to add the SM.79-II or Cant Z.1007 I'd have fully agreed with you.
In the last sim I was playing there was a great number of ppl working on new airplanes (every year we was used to get 10 new aircrafts) but there was a simple rule, the airplanes had to be produced in large number (don't remeber exactly that host deadline) but was something like 5'000 at least. Any other which got produced in a smaller number was out of any wish.
If I well remember in late 1944 there was only 20 meteor flying as ground fighters.
If the limit is 5000 they couldn't possibly add 10 aircraft a year to a WWII sim. Only two Japanese types exceeded 5000 and none did if you limit it to 5000 of a given mark. Very, very few aircraft of a given mark exceeded 5000.
FYI, HTC has a limit too. It has to have been in series production (i.e., no prototypes), in service in squadron strength and has to have seen combat. The Meteor Mk III meets all of those criteria.