That just sets the privacy level for the post, selecting if an individual is allowed to see a specific post. What the parent commenter is talking about is whet

That just sets the privacy level for the post, selecting if an individual is allowed to see a specific post. What the parent commenter is talking about is whether the Facebook newsfeed algorithm will even show that post to the people allowed to see it in the first place. Or will Facebook just hide that post from your friends in favor of ads, clickbait, etc. on their feeds.