For years, the acronym was LGB. Then they added the T to make LGBT. That has been the standard acronym for years. After those four letters, all bets are off: there is no standard. People add any number of letters after that to include other groups.
My own feeling is that anything more than four letters becomes unweildy and unpronounceable. I can handle LGBT in the spoken word, and even LGBT+. But after that, I pronounce any longer combinations as "queer". Around here, a common long version is LGBTQIA2S+. Really?
I understand the feelings of those who feel left out of whichever version is used. But that is going to happen no matter how many letters you add.
I don't get offended if people use longer versions, nor if they use shorter versions. Obviously, being trans, it would concern me if the T is left out. But there are occasions where what is being spoken about is not relevant to trans people, so leaving the T out may be appropriate in those cases.
The bottom line, I think, is that there is no one correct version.
