I agree he'll probably start out relatively slow as he did in AA last year, but dude still put up only the 5th 20/40 season for a teenager of the modern era. Also, the 112 wRC+ with the half-season tacked ball is still better than what Giancarlo Stanton, for example, put up in AA at age 19 and he went on to have a big rookie year.
Thing that matters most to me by far about his ST (and ST stats in general) is his K%, which was at 19%. That's exceptional, especially compared to other top prospects who had big springs like Langford (24%) or Holliday (31%), and a major sign he's not going to get overwhelmed by big league pitching out of the gates.
I still think he's going to start out slow because despite the superb BTB he's still learning to only go after pitches he can do damage with and thereby minimize some of the weak contact you saw, but once he figures that out he should take off.
I think a reasonable floor is Bobby Witt Jr's rookie season with a reasonable ceiling being Julio Rodriguez's rookie season. Split the difference and you've got somewhere right where he was last year and then this year in spring training with a 105-120 wRC+. I'm personally on the higher end combined with his baserunning value. Hence my ROTY prediction.