Ok, you are a bit too inside your head, I think....
All are done, in context, to reduce the stigma of infidelity/adultery.
The only 'stigma' there is - is self-imposed. Humiliation of a cuck is a trope that works. That's all. So that 'stigma' of cuckolding is a necessary part of stories about cuckolding. It's just makes them better - more emotional.
It could or could not transfer to IRL RP.
But outside of role-play, it's a stigma in the same way BDSM is a 'stigma'.
What, domestic abuse makes you hot and bothered, you piece of shit?
No, it's not. That's not how excitement works.
For normal people, there's no 'stigma' when you tell them that you're into BDSM, or that you're gay, or that you're into humiliation.
It doesn't matter. Maximum they'll say it's cute. That's all.
If your girlfriend will come up to you and meekly offer you to fuck her friend while she watches - what, you'll throw a tantrum that 'she doesn't love you anymore' and 'you should break up'?
And get a free ticket to a mental asylum..?
Yet it is an integral part of a lot of stories.
Precisely because role-playing that 'stigma' makes it hotter.
So what I'm trying to say: there's no need to 'reduce that stigma' - it's the opposite. If you already use it in your role-play - you need to amplify it. Or you don't use it at all.
And there's no stigma outside of role-play.
If someone stigmatizes 'being gay' - you don't 'reduce stigma' with different words, do you now? These are crazy people. They need reeducation.