I know the some do, but in general they don’t. If you look here 5 of the 6 models have a compensated wrap-around bridge, and only 1 has the separate tune-o-matic bridge and stoptail. Then if you just look at all the SG listings the humbucker models pretty consistently have the two piece system.
But then when you look at P90 Les Pauls, it’s much more mixed with both bridge styles.
In fairness, their “traditional” way of making necks isn’t the greatest and is wasteful, they cut the whole thing including the angled headstock from a single piece, creating a horrific weak point where the headstock meets the neck (Google “broken Gibson headstock”). Could easily be remedied by using a scarf joint instead. My SG took a spill once and luckily it was spared, but its a very real concern with an authentic Gibson.
Side note, its also an easy way to spot a fake, or a repair, assuming the neck has a transparent finish