I'm interested in why it matters to you that the word gay be included. I'm with you on deception. People need to be honest about what they want. But you seem to be of the opinion that people can't be both dominant and bi, or both alpha and gay.
The reason many see the power play role as "not gay" is that the men don't seek each other out as play partners. In many cases, there is ZERO sexual attraction. In these cases, the bull wouldn't let the man suck him off alone. If he wasn't doing it as part of some power play, to show dominance and/or make a fantasy happen for the wife and submissive, he wouldn't do it at all. I've heard one prominent bull (who, like it or not, is a respected voice in the cuckold lifestyle) describe it on podcasts like this:
"Some bulls will do it as a show if dominance and power exchange, but she has to be a part of it. She better not get up and go to the bathroom. When the woman isn't there, it becomes something else and that kind of play stops."
In BDSM and power play, hierarchy, obedience, etc. can trump things like sexual attraction. It's not always about deception. Some of these people aren't hiding anything. Many are very upfront about not specifically looking for male-on-male contact, but being willing to explore certain things in a dominance/submission context. They're not in the closet or in denial, they are describing the way they think and feel about their own experiences.
It's clear that YOU consider a man gay if he says, "come here and suck this dick, cuck. Get it nice and hard. I'm gonna use it to fuck your wife's white pussy, the way she's been wanting to get fucked for a long time. This big dick is going in that woman over there, and you're not going to stop me, are you?" It's absolutely fine if that's something you're not into, and you can call it whatever you want to call it. But clearly, there are people here who consider it less about a label. In a lot of cases, the reason it's something people want to try is specifically BECAUSE they are not attracted to other men. What they are looking for is taking a submissive concensually outside their own comfort zone. "I know you don't WANT to suck cock, but your Queen just told you to. You're not going to disobey her, are you?" It's no different from letting yourself be strapped to a bench and spanked or flogged. The idea isn't that you like all pain. It's that it's exciting to sustain discomfort at the hands of someone else as an act of submission.
Obviously, consent needs to be discussed. People's limits need to be known before play ever starts, and respected. If someone says they don't want any male-on-male contact of any kind, that should be enough to tell ALL INVOLVED, be they top or bottom, Dom or sub, male or female, that there's a hard line in the sand that won't be crossed. It's not a thing you can try again in the moment. It's off the table, just like any other hard limit.
Is a man sucking another man's cock an act of bisexuality? Absolutely. So it's fine if that's all it takes to make someone "gay" in your eyes. But I'm not sure what you're trying to accomplishing by making sure others know that about you. What difference does it make to try to correct someone, who just told you that to them it's more about power, to make damn sure they know that YOU think that's "gay power?"
TL;DR: not all who say, "I'm not gay but..." are in denial or being sneaky. Some just disagree with you about the nuances of an activity you are obviously aren't into and don't want to understand.