Thoracic Outlet Syndrome (TOS) is a very common set of posture dysfunctional patterns. Adson’s, Eden’s, & Wright’s tests are designed to assess TOS.
It is essential to exercise caution when working the anterior neck. However, this should not prevent therapeutic manual therapy work to the anterior neck.
There is an old saying that no posture is bad unless you get stuck in it. The problem is that the thoracic spine often does get stuck in bad posture.