There is no policy mandating the use of content warnings (not to be confused with NSFW on images) on mastodon.social. It's between you and your followers. You shouldn't demand that someone use it for politics (but I believe politely asking is OK)
@jd@Gargron ... and there's a mute button if someone's soapbox is a thing you're not interested in so there's really no justification to bug people about what topics they post on.