I'm sure it will. Now you drop down the rabbit hole. I am not, and have never been, a lawyer, but the problem seems to me to be not so much about the rifle. A few people will buy one, and by the time they get through the first thousand dollars worth of ammo and into the second magazine, it will occur to them that it is a really bad idea. The problem is precedents. I don't know what the eventual effects of setting a bunch of precedents will be, but it can't be good.
Joe Shooter goes into his local Tactical Mart O Rama and buys a rifle. He has to fill out two 4473 forms. The lower passes NICS with no problem, the upper goes into the black hole of BATFE Bureaucracy and gets incorrectly rejected. So now he can buy part of the rifle, but has to appeal the other part.
Joe's brother Bob buys a similar rifle at the same place, and has no problems with either of the forms. He goes out and shoots it for a while and decides it is a really stupid firearm and he doesn't want to mess with it any more. He takes the upper off and puts a 6.5 Grendel upper on instead, and happily shoots it for years. Some time in the future he trades the entire (now 6.5 Grendel and only one firearm) rifle at a gun show. Anybody want to bet that somewhere in the bowels of the BATFE database, that lower is linked with the .50 upper gathering dust in the back of Bob's gun safe?
The third Shooter brother, Cletus, lives in a semi-communist state and is limited to purchasing one firearm per month. Obviously, if Cletus is interested in something like a .50 BMG upper, he has a bunch of AR-15 lowers already, but maybe not. He shot Bob's rifle before he put the Grendel upper on it (Joe is still waiting on his appeal), and wants one. He can only buy half of it this month. He has to wait a month to buy the other half.
And another one. The world is hit by an alien stupid ray, and Schumer/Pelosi win the presidential election. Now, we all know that the eventual goal is to outlaw all firearms, knives, pointed sticks, and rocks, but first up is a ban on Evil Assault Weapons. Because the Blunder Twins have no imagination, the ban will be modeled on the California ExtraConstitutional Excursion. Which one of the two firearms represented by the single rifle is going to be designated as the E.A.W.? There is only one Dangerous Pistol Grip, one Threatening Large Capacity Magazine, one Concealable Collapsible Stock, and one Sniper Flash Suppressor. Most of these attach to the lower, so the administration is okay with .50 BMG uppers, right? Unlikely.
Now that they have all these marvelous precedents in place, what's next? Obviously, serialize all AR uppers and treat them as firearms. Otherwise you are discriminating based on caliber, and that must somehow be RacistSexistHomophobicInsensitiveBad. Because everyone knows high capacity magazines cause school shootings, serialize all of those and treat them as firearms too. Some folks convert semi autos to full auto, right? Not if BATFE controls trigger groups as firearms. That would make it more illegal than it already is, so nobody would do it any more. There is no legal issue with any of these, because it has now been established that a single firearm can have multiple serial numbers, every one of which is legally a firearm in its own right.