BaseballAmerica has him with a 70 grade arm. So far this year, his fastest recorded throw from short is only 88.1 MPH (
https://baseballsavant.mlb.com/savan...r-fielding-mlb). We should have a better idea after he has at least 75 throws from the left side of the infield.
I agree with your approach to how you've rated De La Cruz. Too many people are getting ahead of themselves and trying to make this guy a top 10 player in the league after less than a week of action. He's had a great debut thus far, but a lot of that is because he's amped up from the promotion and teams only have minor league scouting data on him.