Well...Auburn just beat the #3 team in the nation, and Morant put up 25 points, 8 rebounds, and 7 assists in that game. Murray State only lost by 5.
He just put up 36 against Belmont, which has a slim chance at an at-large tourney bid.
The only other major conference team he went against is Alabama, and he scored 38 in that one.
He was in a completely different role as a freshman, but did just fine against West Virginia in the tournament.
I'll agree that he is unproven against top talent, but just because of a lack of opportunity. He has looked good-to-great against the top competition he has faced.