Can Damage or Compression of the Great Auricular Nerve Cause Tightness/Numbness Post Surgery?

The greater auricular nerve is a sensory nerve that supplies sensation around the earlobe and the jawline area. Injury to this nerve would manifest immediately after the surgery in the form of loss of sensation in these areas.

So, your delayed symptoms are not likely to be related to an injury to this nerve. Instead, these symptoms may well be related to wound-healing and scar maturation which typically does occur several months after the surgery. Gentle massage, lymphatic massage or ultrasound therapy may be helpful in improving the feeling of tightness. Any numbness that you are feeling may well have been present earlier after the surgery but not been as noticeable to you at that time. 

Injury to the GAN typically manifests immediately after surgery, not months after.  There is no imaging that can detect the problem and no treatment that can make the nerve regenerate faster, but sensory nerves do continue to regenerate for years after the injury