I might argue Acuna was slightly unlucky with a BABIP over 30 points below his career average. And that's a little scary for opposing teams considering he was pacing for his best season offensively. He might have surpassed Freeman as MVP over a full season if his BABIP reverted to career averages.
His HR/FB rate was 32%. I suspect you are right about the BABIP regressing up, while the HR rate will likely regress down. The projections mostly agree as evidenced by projecting a higher BA and a lower SLG.
The really promising thing about Acuna’s 2020 is that huge jump in BB rate. If his increase in K rate was a result of him being more patient, then he might be in the process of turning into a truly elite approach at the plate to go along with his plus-plus power. When guys start to couple 40 HR power with a 15% BB rate, that’s when they start winning MVPs. Hopefully that dip in contact rate was just a blip.