Yes, let's break this down. The only "different" medical care transgender people ask for is treatment for their gender dysphoria, which may include hormones and eventual surgery.
If they receive that treatment, it's because doctors find it medically necessary, or at least justifiable. If insurance covers it, it's for the same reason.
It's covered for federal prisoners just like their other medical necessities. But, like other medical necessities for federal prisoners, it is subject to pretty extreme scrutiny by BOP, because they're in the business of denying healthcare whenever they can, 8th Amendment notwithstanding. They routinely discharge cancer patients rather than foot the bill for their treatment, as their continued incarceration would require.
We wouldn't begin to question other people's medical diagnoses and treatments across the board unless they were "icky trans." Nor would we accuse the medical community of some vast conspiracy unless it was some lunatic right wing patrioteaglefreedomgun issue.