@YachtRocker my son is at a school that has a post grad program. They are placing some players but no matter how you cut it, it's an expensive way to buy time and doesn't always translate into better outcomes (some still didn't get offers, some are going to JUCO or CCs and I don't know what kind of money they are getting when they go D3-D1). It also really seems like a shame to do a PG year given your son's academic profile. With his grades and scores, it seems like you can target HA schools and work with his travel team and/or high school coach to initiate some conversations so that he is on teams' radars once he comes back. If his size and metrics translate into in-game performance, he will be the rare bird that will get noticed even late in the recruiting game. I know it's not the norm but I know a 2021 who just signed with USC (Southern California). Definitely communicate with the teams he is already in touch with. Don't necessarily signal an extra HS year unless you are absolutely sure he needs it. Unfortunately, TJ is so much more common than it used to be that I don't think it will turn away as many people as you think. A close family friend of ours tore her ACL her junior year and is still considered the top women's basketball recruit in the 2021 class (headed to UConn).
Please just do me a favor, don't rush him back so that he can be seen. I echo everyone's sentiments about getting him the best care (which it seems like you are) and make sure his focus is on getting healthy and not worrying about college baseball other than using it as a focus for his rehab. I know it doesn't seem like it now but while injuries can seem completely devastating at the time, in the end they can set a player on the right path and s/he will see long-term blessings in the temporary pain. Don't tell RockerJr. that right now though...he might want to punch you in the face if you do. LOL
One other thought. It seems as thought you've conflated PG and reclassing. If he decides to "redo" his junior year at a private school, then you would reclass him and change his graduation grade to 2023. You would be on the hook for two years of private school. If you decide you are going to do a PG year, from what I understand, he would stay a 2022 until he goes to the new school and then he would be a PG. It would actually give you a chance to see how things shake out and you might decide you don't need a PG year.
Finally, on the draft, I'm no expert but from everything I've read age will not hurt you vis-à-vis the draft. It does give you less "time" to make it into the Majors (all things equal a team will give the 22 year old the benefit of the doubt over the 27 year old). I would not factor the draft into any decisions you make because there are so many steps before you get there. As a parent with a draft eligible senior, it's stressful enough when it's upon you and you HAVE to think about it. Try not to think about it before you have to or you will go crazy. That's just my two cents.
Wishing your son all the best through his surgery and rehab.