Why can't we (the soldier or leader with HIPAA) track the status of a MEB packet?

If you are asking about an individual checking their own MEB status that would be a question for your case manager or PEBLO. I went through the process myself and I know the stress. But you can look at it in simple terms. There is the time before package submission and after submission. You should get regular updates from both while working towards a package submission. Once a package has been submitted it could be up to 6 months before a determination is returned. Don't expect much communication during the post-submission phase because ultimately you are in a queue. You won't get updates until a determination has been made because all it would tell you is that you are still in a queue waiting to be processed. But once a determination is made and you are briefed on the results you'll have to make the choice to accept or appeal the findings which means you are appealing to the board to state your case. Maybe you want a higher percentage or maybe you want to be found fit for duty. Whatever it may be that would be the time to speak your peace.

Contrary to your statement (as well as the condemnation of the Army/DoD as not being a professional organization because you didn't know the resource available), there IS a dashboard that Soldiers and Commanders can use to track the status of the IDES process.

It used to be known as MyMEB when it was under AKO, but it's moved to the Command Management System (CMS) on the Medical Operational Data System (MODS).

The Soldier's resource is https://cms.mods.army.mil/cms/protected/report/soldierDashboard.aspx
The Commander's resource is https://cms.mods.army.mil/cms/protected/report/commanderDashboard.aspx

You'll have to access it from a .mil domain as MODS is restricted.

Talk to your peblo.