For most who have TJS, initial recovery is about the same, but for position players the throwing program is shorter, I heard about 8-9 months until you can be back on the field. And there still is a time frame after you get back to throwing accuracy, which catchers need. I understand there are a lot of position players that have tears or strains, my son has a few friends who have tears (slight), but not bothered much or unable to perform as a pitcher or catcher might. They were drafted for production at the plate.
If it were my son, I would have him speak to the coach to find out if there is another position he could also play and continue to hit and finish up his last year, unless they are willing to get him a medical waiver, but most coaches won't for seniors. He may get some interest from MLB if he has a good bat, but you will have to fill out medical information and not hide anything. Some team may be willing to rehab him, but not pay for his operation.
I am sorry for your son's injury, best of luck.