alabama-fort-rucker-vaccination

Not sure where you read this. The Washington Post article you posted certainly doesn't say anything about vaccination being mandatory, in fact the last sentence of the article says, "Vaccination against the coronavirus remains voluntary for all military personnel and Defense Department employees while the vaccines await full approval by the Food and Drug Administration.". What it does say is, that the post policy is "authorizing leaders to ask for proof of vaccination of service members not wearing a mask while on duty". Asking for proof that you've been vaccinated if you aren't wearing a mask is wildly different from requiring the SM to receive a vaccination.