The US is an extremely diverse society and attitudes towards LGBT people differ hugely across the country. LGBT travellers may be affected by legislation passed recently in the states of North Carolina and Mississippi.
The change appears to have come at the urging of Gay Star News, which criticized the Foreign Office for previously offering warnings to LGBT travelers visiting countries like Russia and Turkey, but not Western allies like the US.
The news site notes that trans tourists face the possibility of “being arrested and held in a male prison if they’re a trans woman and a female prison if they’re a trans man” should they inadvertently violate American law.
As always, it’s important to learn a foreign country’s unique customs before visiting. In the case of the United States, that apparently means lessons in vaguely defined but fiercely defended state-sanctioned bigotry.