If the decision is even close or a coin flip, I say send him to College. There are 3 kinds of minor league players. Prospects, Non-Prospects & First Round Picks. If your boy was a possible first round pick, you would be well aware of it by now. It sounds like he is a real nice player & they are feeling out his level of interest in Pro Ball. Not everyone has the College option or desire. Certainly no harm in sending him to pro camps or workouts just for the experience.
Here is the reality of Professional Baseball. Unless they spent a ton of $$ to sign you, you are basically thrown into the "shark tank" to grind it out against the best of the best and make your bones. Nobody really cares about you & nobody really tries to help you (Unless you are a big $$ kid). There is limited or zero instruction & direction provided. There is no concept of team, with the exception of the Manager who can possibly advance by winning. When I was in AA, we started a "Boot Hill" for departed players. By the end of the season, there were 26 name tags of players who had come & gone (up, down, released) taped up on the column in the center of the clubhouse. The players do not give a rip about winning. The games are all about individual performance and advancing. Nobody, including coaches, wants to be where they are at. Everyone is looking to get to the Big Leagues.
The days & bus rides are long. The hotels are often bottom shelf (Rookie Ball through A Ball mostly). I recall checking into a Little Rock hotel with junkie needles left in the sink. There is tons of down time away from the park. You spend your life in 4 places. Hotels, Ballparks, Buses/ Airports, Bars / Restaurants.
If you are the type who refuses to sit in a hotel for days on end, there are 2 main types of distractions. Alcohol & women. Needless to say, maintaining a committed relationship is "challenging."
Now, take all this & toss in a healthy dose first time significant failure when he confronts equal or better talent after owning HS.
Contrast this with the College experience, particularly if the maturity level of the player is not at a high level & this decision is easy to make. The $$ needs to be "exceptional" & even then it can be a mistake to sigh out of HS if the player is not ready to face, and excel in this environment.
So having said all of this, I will add that I have a 2021 who has serious Div 1 interest already. It would be his decision if it came down to it in a few years but my STRONG advice would be College unless First Round, Slot $$ / College Plan & he was at a maturity level to cope.
In addition, I would also demand that his Minor League contracts be for a sum between maybe 25-50K (even if this took away from bonus) so he did not have to eat his Bonus $$ to survive. He could learn how to budget his $$, pay bills & actually have an income as opposed to the $12K / Year or whatever crazy $$ they pay now for first year MILB players.