The waiver request is kind of like the appeal. DoDMERB isn't the one that determines severity of the condition, nor does it give waivers. They go down a checklist and DQ (or pass) based on your answers and your medical exam.
If a SA is requesting a waiver, consider that a good sign. They won't request a waiver if they didn't think they wanted you. Once you get all your information together (they will send you a letter telling you what they need), DoDMERB scans it in and sends it to the SA waiver authority. THEY will be the ones to grant a waiver.
It's good that you already have letters that you've sent in, though. It MAY be enough for the WA to grant the waiver. Just watch your DoDMERB portal. That gets updated more quickly than you get the letters.