On a Lippert-made frame? I certainly wouldn't bet that it =was= square. Only way to check 100% would be to un-skin the front end and check the pin box mount against the frame itself. Yes, there might be enough slop in the trailer-side holes to square it up a bit, but I wouldn't worry much about it. I =would= go on record with both your dealer =and= the mfr. (maybe even a certified return-receipt letter, signed by a certified RV tech and/or the dealer's supposedly-factory-trained tech), so if anything does happen, you've given them notice of the defect.
There was a post on here a few years about where someone was having tire wear issues, so took his FW in for alignment. First thing they found was that the center of the king pin was a full 3/4" off-center. Think that might cause some axle alignment issues? Yep, Lippert-built frame.
Personally, I don't think you will have much of an issue, especially if you have a tilting-head hitch, like a B&W Companion.
Lyle