everything may have to be reconsidered under the newly built structure, I assume. The senior management may not have thought through all details.
Your supervisor acknowledged your efforts and performance by saying she would endorse your promotion. But she is not the ultimate decision maker on promotion. I don't see why you complained so loudly.
If you don't have a buddy at the HR or other resources within the company, your direct supervisor will be your only and last resort. As such, you'd better work closely with her and help her around.
I strongly recommend you to conduct a formal discussion with the HR. Ask them what you may have to work on to deserve a promotion.
