It's a valid consideration for a trans person to be interested in joining a LGBTQ...etc. guild.
That person may be interested in building in-game friendships that include some conversation involving some degree of knowledge about their out-of-game life.
And the experience of being trans affects a person's present, out-of-game life in many ways. So, it could very naturally be completely relevant in casual, friendly conversation.
And in-game, they may want to know that the 'social space' that they're mostly playing in has an
explicit expectation that people won't be making transphobic comments.
I remember hearing at least one transphobic remark by a player in-game (the juvenile, har har har, 'the mere existence of trans people is funny'-type of "joke"). Oh, and I remember hearing someone making a 'jokey' insult directed at another player suggesting that they might be attracted to male-to-female trans women (the "joke" being that that's supposedly an embarrassing, gross thing). Really, the lazy, trite attempt at "comedy" was almost as eye-roll-worthy as the transphobia...
The transphobic in-game comments are not quite as common, in my experience, as encountering remarks that would be obviously insulting to lesbian, bi, or gay people; but it happens. Really, it's understandable to want to play in a social space in which there's an explicit understanding that bigotry (whether intentionally or unintentionally offensive) is unwelcome.
Just slapping one of these:
onto a guild webpage would repel a lot of obnoxious characters actually.
And maybe follow up with this, lol:
I don't play on Cannith; so I don't know of any appropriate guilds, unfortunately.