As someone who just had ACL reconstruction, I can tell you that they are not "nothing these days." They drill into the two largest bones of your body and attach either a part of you that they cut from somewhere else (patella tendon or hamstring) or they got from a dead guy (probably less likely to work but less pain). They cannot just fix the ACL. They have to make a new one.
Yes, methods are better now, but it would be very aggressive for him to be back for the start of the regular season, although not impossible. Even athletes are not jogging often until months into the rehab. If he is able to make it next year then he will not be near 100% until well into the season if ever.