Self-censorship is the most common form. Most people understand there are consequences to their behavior and words - and they don't want to miss out on the benefits from society and community. You can say what you want, but you can't earn on whatever you say.
A better framework is the start to people again taking responsibility and ownership of their words It isn't about saying what you want, it is about thinking well about what you say. It might not look so different, until push comes to shove.
You're right, everything can be meaningful, but one needs to know what one says, ie thought about it. The result is very likely much more in the grey area so to speak, in longer form to explain the why, far from any black/white statements. Though it is for some ot more poeple almost impossible. I have the feeling - no research done on this - that many people don't really think things through on topics they participate in discussions, or at least tru to participate.
I think self censoring can be a good thing as well since I believe we always have to respect one another. When respect is used in anyting we say, we may not say some things to some people, while we say the same thing to others. It depends on the circumstances and the other people we talk too and with what determines what we can say and what we better can either phrases differently, or not say at all.
There is no need for self-censorship at all. Just express your thoughts in such an 'authentic & eloquent' way that always seed doubts into your interlocutors minds on how to act correctly after having listened or read to you. };)
If you make them think, your 'message' will already have crossed and overcome all barriers. ¡Mission Accomplished! :)