Based on AR 600-8-19 you can remain on the promotion list and the Commander can make the exception. See extract below.
Based on the information provided the Commander can definitely keep you on the list. The question is why did he remove you? You might consider see JAG asking them to prepare a legal opinion that supports your position with all the regulatory information. Then you could consider writing a factual and professional formal request to your Commander explaining your position and asking him to place himself in your position.
If he still refuses you can submit an Article 138 (Redress against a Commander). Remember this should be your last course of action in my opinion as I consider it a Nuclear Option.
Extract of AR 600-8-19
Removal of Soldiers from Promotion Lists 7–44. Administrative removal Soldiers will be notified of removal action, in writing. Once a Soldier is removed the action is final. CDRs will promptly notify the State AG (MPMO) (NGB–ARZ–T for Title 10 AGR Soldiers) and forward supporting documents to remove from a promotion list a Soldier who— .
Is enrolled in the Army Weight Control Program per AR 600–9. CDRs may waive removal of Soldiers who are making satisfactory progress. Soldiers not making satisfactory progress per AR 600–9 and are pending separation will be removed from the promotion list.
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