That's quite a subtle argument and although I can just about see where you're coming
From I think for me describing young thug as an autotune artist is just wrongheaded and unfair. It's not a part.of the aesthetic in any meaningful way and neglects all the stylistic choices and tics which make him interesting.
It's the way he interacts with the beat which is important not the (imagined) textural/timbral quality of autotune
It's timing. It's the suppleness of the line. It's the hanging back and then sprinting to catch up. It's the variations in tone, pitch and volume, it's the (precise to the point of prissiness)
placing of syllables, the open unfixed cadence, the micro hooks littered across every song- lines so rhymically satisfying that they act as stand alone hooks (eg this that, rich shit, I eat fish and grits in dream from barter 6 or, from the blanguage, I'm chilling at the studio these bitchs wanna fuck on the banana boat)
It's the swooning abandoned-to-bliss tone he can reach, gurgling bliss which is unique in rap as far as I know (pelican flys oh gawd oh gawd oh gawd is an example for you)