You only live once.....go to camp.
That said, the hardest question he is going to have to answer is what does he really want....if he reconciles that it is to pitch, then he must evaluate how badly he wants to go to the p5 that is expressing interest.
If he really wants to pitch does he feel that the p5 in question can develop him....all situations are different, but its been my experience that the p5s really (as do most levels) need to win and the focus and effort generally goes into the guys who can get them wins....a redshirt is possible...getting cut is possible
Also, at this time of year, you start seeing freshman transfer out prior to sophomore year. The year end exit interview yields a blunt assessment - you aren't in their plans.
If it's all about baseball and Learning to pitch a juco may be a good option...develop and reassess after year 1 or 2.
Alternatively, if that does not seem to be where he wants to be, the hard question about the p5 is how happy will he be if ball does not work out.....could he live simply being a student at the p5
You also may want to check the p5's commitments in the 2020 class on perfect game.....specifically pitchers....look at their current roster and see how heavy it is with 2019s and 18s...not only pitchers, but the overall roster...that'll give you a good idea as to the type of numbers game he would face as an incoming freshman...they can only keep 35. They only get their through the draft, or cutting/redshirting.
The other piece of info worth noting (that I picked up at a camp from a p5 coach) related to choosing/evaluating the right school. He indicated you needed to evaluate the four following areas:
Baseball - Whats the best opportunity to grow/develop and how will you fit on team
Education - is it a good fit, i.e. majors, level, support
Social - is the geography, size, culture of the school right for you
Money - can you afford it.
In the coaches opinion baseball was the most important piece of the puzzle.......the rationale was that if the place you spend 40 hours a week does not work for you, your overall experience will be miserable and your education, and social experience will suffer.....I hadn't thought about it from that perspective..for our family it was mostly about education.....but for the most part I've found it to be true and a useful way to sort through the opportunities.