The type of gullible person that accepts these false beliefs about issues such as climate change and immigration isn't going to change their mind simply because Facebook starts censoring such content. Many people held such views before the rise of Facebook and other social media empires. Such views have been transmitted over old school media such as conservative talk radio shows for decades before the popularization of the internet.

All that is happening is a change in medium used to propagate such views. These people in question are only engaging with such social media channels because they find views that support their beliefs. Should such views be censored, they'll simply seek out other mediums.

I think the core problem is that many of these issues have been too highly politicized and now people can only engage with such issues on an emotional level. They only ask whether a view supports "their side" on the issue and care little for the actual facts.

Note, I don't even believe this behavior is limited to any side of the political arena. I've seen friends ostracized for simply considering positions such as the leftist argument for strict immigration standards to ensure a country has ample resources to care for their existing citizens and only takes additional members that will be a net positive contribution to societies available resources.

All in all, I think it is beyond the ability of social media empires to help gullible people become less gullible. All they can do is decide what content for gullible audiences they will allow on their platform. The more they restrict content, the more their user base will shrink as people seek out alternative mediums to find the content that supports their existing beliefs.