I do not clearly feel any such thing. But I did make some assumptions based on what she said and extrapolated based on decades of knowledge and understanding. She was free to correct me at any time.
The OP said "I want to be supportive but just don't know where to start."
She immediately worries about supporting him, rather than getting support for her own feelings. I considered that a red flag and it sounded like a woman who has been programmed to "Be kind".
Could be wrong, but then she went on to say: "I just feel hurt because I can see him thinking he has hurt my feelings but it hasn't." which again is all about putting his feelings above her own.
The OP also said: "We have friends who are of varying sexualities and friends who have transitioned so it's not a new area. I just want to make sure I support him well as his wife." Not an environment she might feel comfortable saying "I'm not ok with this."
Maybe she's not subjugating herself, but from the tiny amount of information she has given and the very few lines she has written she still manages to mention his needs and feelings repeatedly.
And I didn't jump from "Does your husband want to have sex with other men’ to ‘are you ok with a sexless marriage’.
I said: If he wants to fuck men, are you ok with this? If you are not ok with him fucking men are you willing and happy to lead a sexless life and just stay together as friends?
It's not helpful to misrepresent what I said, it makes you sound disingenuous.
And yep, anyone can be attracted, or not attracted to anyone for any reason or none.