Does a criminal case in PA take this long?

While I do not practice in PA, I can answer this question in general terms that are based on my experience here in NJ. Case processing does take an extraordinary time, but the example you list seems overlong given the stage of the proceedings.

Your son (respectfully it cannot be you) needs to contact his lawyer about this. If this were my client here in NJ, I would place a call to the PD lawyer, and if I did not get through, I would leave a clear message stating that the matter has not been resolved and that I wanted a return call. I would follow this up with a call to the PD lawyer over a several day period. I would use a phone where I could get a detailed printout showing the call, time, etc. If there was no response, I would follow this up with a letter to the PD lawyer sent regular and certified mail/RR. If that got no response by the time I got the CMRR back, I would send a second letter, indicating the steps I had taken, with a cc to the supervisor of the lawyer. If that got no response, I would suggest your son consult with an experienced criminal defense lawyer admitted to practice law in PA to see what assistance the private lawyer could give in regards to getting this case moving. Good luck.

DISCLAIMER
This response does not constitute legal advice. Given the nature of this website, it does not create an attorney-client relationship. This answer is provided solely for informational purposes, for you to use as a starting point when speaking directly with a lawyer in your State. I urge you to immediately contact an experienced criminal defense lawyer admitted to practice law in your State before you make any decisions about this case.