Could sharp pain between my shoulder blade and spine be attributed to my brachial plexus injury and suprascapular nerve compression.

NO. As the brachial plexus comes from the cervical spine, while the area mentioned (between spine and scapula) is supplied by nerves from the thoracic spine. One could have both lesions though. See your spine specialist. Good luck.
Brachial plexus inju. A brachial plexus injury can lead to pain between the shoulder blades, though not common this can occur.