The way the MLB draft works is quite a bit different than other sports due to the bonus pool and leverage of players. ADC is not going to come back for a 5th year and teams know it, so even if he did gamble and come back, he isn't getting more than $2M even if he hits like he did as a sophomore. Add another year of age and the teams who use draft models would ding him even more.
ADC would be almost 23 in next year's draft. Coming back would cost him money, even if he hit like a mad man.
He's a bat-to-ball prospect who isn't an elite defensive major league catcher with limited physical projection. I never saw him as a top-10 pick unless he wanted to sign for under slot anyway.