The way I'm reading this, the only person with the power to dismiss someone for being transgender is Defense Secretary James Mattis. While anyone having that power is honestly for all intents, bad, with the way the military works this would mean almost no current trans service members would be removed. I say this based on the fact that the paper work is unlikely to ever be filled out, and if it was anyone in a long chain could stop it by denying the paper work. It would have to go through several commanders, company, battalion, brigade, and garrison to even be sent to DC and make its way to Mattis. Any service members in right now most likely would be able to continue serving.
The main issue would be if MEPS can deny someone entry, or are they still allowed to let new soldiers in? I also don't see any language stating the Military would stop treating Gender Dysphoria. I can only hope that the way I interrupt this is correct, and that is it appears Military advisors are trying to appease Trump while keeping the ability to let trans individuals serve.