Not quite. Shotgun-pistols are NFA weapons which fall under either the AOW class or SBS class, depending on configuration.
.45lc/.410 revolvers have rifled barrels, thus are treated like normal .45lc revolvers.
This same reasoning does not apply to rifled 12g shotguns; because they are larger than .50" caliber, you can not build a "12g pistol" that doesn't fall under NFA simply because it has a rifled barrel. If you were to really, really push the subject with the ATF, it would probably go something like this:
"It's not an NFA short barreled shotgun, in fact it's not a shotgun at all! See? It has a rifled barrel!"
"Okay, fine, you wanna play that game? If it's not a shotgun, then it's an NFA destructive device because it's larger than .50" caliber."