Oh, they're not encouraging stopping the identification of gay and lesbian, no, they're discouraging the use of the more formal and rigid homosexual. Obviously a gay trans man is gay if he like masc presenting people and a trans woman if she likes fem presenting people, and those people inclide nonbinary genders as you know.
Gay and Lesbian are rigid definitions to 90% of the population, but not people of gender. People of gender use them to feel queerer, a heterosexual appropriation of a "cool" identity and usually a fetish. They're trying to outlaw the proper scientific classification since "homo" is used derogatorily (I've met a young gay sjw man thought homosexual itself was a slur!) so it is more ripe for the toppling than gay and lesbian, the coolest identities outside of transbian and gay tboi on the planet.
They can't do this to heterosexuals yet since there's no body of language control to bully all of them into compliance. Gay journalism is smaller and essier to bully. Even if it gets accepted by journos or even the dictionary, heteros are too preoccupied with everything fucking else to remember they're supposed to say gyno/androphyllic. Hell, same with the lesbians and gays not on the goddamn internet.