I don't think it's a good idea to tell people. The fact is pro-choice is very controversial and most normal people who love you will be very upset to hear that you "want to leave them." Of course we know that it's a fully selfish decision (in that we rarely choose to ctb in order to blame, hurt or take revenge on those who love us) but other people may interpret it as "message" to them. They feel guilty and helpless, which sucks because they love you and they may feel at fault if you ctb and they know they could've done something for you. Grief can be very deep and often involves feelings like that. Blame, helplessness, regret, revenge, etc... It's normal for people not to understand. After all, there's plenty of people who don't support euthanasia for terminal illness.
If I ever tell someone, it'd only be my mental health provider. Though they are required to lie to you and most will not tell you that you may be struggling with mental illness forever. They tell you the opposite in spite of the fact that it's pretty well-accepted that most mental illnesses are chronic and may progressively worsen.
I think in general it's just super taboo to understand ctb and be pro-choice. We all have that survival instinct against all logic and rationality, even for each other.