I've struggled with the ethics of forming any more relationships more and more as the reality of what I'd have to eventually do became more apparent. Honestly, my last (technically current, but she's going to end it when she speaks to me again) relationship was initially based upon listening to dumb therapist advice about trying again to make new friends/relationships to see if it brings me happiness. I'm not saying the relationship was fake, I genuinely love her, but it could never bring me enough happiness to make up for all the pain of life.
At this point, knowing it will end, I find myself committing to never being in another relationship because I just know that no one will be able to accept that I may ctb without taking it personally. In turn, I am hurt by the hypocritical lack of empathy that I receive from them. Further, it's an inherent trust destroyer to know that you have to keep secrets from them but that they'll blame you for it even though you're doing it because it's what they say they want. It just seems like it inevitably leads to making things worse for everyone in my experience.
So, I just don't see the point unless you're completely certain that they're on the same page as you in terms of how you think about whether people should ctb or not. I don't believe in perfect certainty, but that's my own perspective. There's also the fact that people often change their minds.