I guess, but that's some pretty unnecessary gatekeeping when one is dealing with the definitions assigned by a secular government who, in your analogy, is not in the business of evaluating wellness and healing practitioners' truth claims at all. All the various outgroups that became heretics when a very political conference wrapped up in Asia Minor didn't suddenly stop identifying as a Christians, and the fact that some provincial American conman steeped in Great Awakening Protestantism inadvertently reinvigorated some of their ideas 1500 years later doesn't make it nonsensical for his marks and their descendants to self-identify as Christians. The state has a very good reason (and no bar) to evaluate whether a given "healthcare provider" is going to harm the public by claiming certain titles, but the situation with religion is very different, particularly for a bit of minor military bureaucracy (historical contextisn't even really relevant here). Unforced error by the MAGAs.

Now, IMHO Mormonism is a pretty toxic, high pressure religion, and it believes some shit that strikes the modern mind as particularly goofy, but it's a religion with a creed that's very clearly arising out of the Christian tradition. If you want to take different magic sky-daddy theology at face value, then sure, within that framework you can reasonably draw a line and declare anyone on the Arianism line of it as "not Christian," but that's not the US government's job. Absolutely not the hill for the Department of Defense to pick at all, much less to die on, but if it makes some Mormons disillusioned with one oppressive cult of personality, then that could be a good thing.