Poll results aside, if you go through the various threads since the problem was originally discovered, quite a few users have reported having received T81's with canted barrels. So, there is definitely a problem with these and you either get lucky and get a good one or you don't.
That being said, it is more than likely true that the canted barrels were deemed "acceptable" quality control on this type of a military rifle for the Chinese, as they have no provision for receiver optics and if one rifle wears out prematurely due to a skewed trunion, they'll just scrap it and reissue another to a soldier. When these were in service, the price per unit was probably under $10 to produce and all the troops were pretty much disposable, so not giving a sh*t about geometry as long as everything "worked ok" was probably the way they operated.
The thing that is surprising though is that this receiver is of a new manufacture (semi auto only, made for export) and yet so little attention was paid in making it. When a rifle is manufactured for the civilian market and is no longer "disposable", quality control should go up a few notches. It's a 2017 commercial rifle manufactured to 1970's Chinese standards... very disappointing, to say the least!