To me, this seems to be a statement reminding insurance carriers that they can not deny coverage to TG people under WA law, not a declaration that SRS, FFS, or VFS must be covered. I think it applies more to any normal service or benefit that would naturally apply to a CIS person in their birth gender being made available to Trans* in their identified gender. While this is a good reminder, it doesn't seem to remove exclusions for other reasons such as deeming SRS experimental or cosmetic, nor does it address which services are deemed medically necessary for TG individuals.
Still, the tide is turning, at least they can't deny us coverage for day-to-day medical and Rx needs... Now if they would just make it part of Medicaid it would really break things open for us!