Yes, they would be gay, and here's why:
If they are loveually attracted the "futanari" part, that means they are into the whole package. Being a woman and being attracted to a female's physique makes them gay, regardless of the richard involved.
The same is with men: Being a man and being attracted to a "female"'s richard makes them gay, regardless of the face/fake tits involved.
If you boil it down it's really the overall concept of it that makes you a homo; no straight person is turned on by a trap having the same genitalia as them. They might be turned on by the opposite gender features, but if you prefer traps to non-traps that's gay.
I still can't believe this has to be said, both in that they're obvs gay and in that a conversation like this should never have to exist. ._.