Now you just propagate propaganda of social networks. The non-legal definition of a publisher is entity which collects, selects and packs content. You see, the very moment social networks, forums and other platforms choose to moderate the content by removing "inappropriate" content they effectively become publishers due to selectivity. You just cannot have your cake and eat it too.

Either you do not filter the content and shift responsibility to actual content creators (I have no idea how it would be possible to implement that without ditching the very concept of "feed") or you select the content and take on full legal responsibility for what you selected.