Is the stigma of post-traumatic stress disorder still prevalent in today’s military?

Yes, I do believe the stigma is still prevalent, not only in the military, but in the civilian world as well.
While great strides have been made in REDUCING the stigma, much work remains, primarily in educating people what PTSD is (and more importantly what is ISN"T). Unfortunately, I believe it will take years to accomplish a significant reduction, and I'm not sure we will see the stigma every be completely removed in our time.