Yes, but he wasn't going to play either way (staying or going). So he had to have left OSU to not only get surgery but to recover from it. If he's enrolled at the University and finishing classes while also leaving the team, that's a different story then leaving school AND the team to rehab with a super specialist.
Bosa could have had his surgery, finished school, stayed on the team, gone through rehab, and worked out for the NFL. How would that have dropped his stock?