With thousands of posts every day, many of which are absolutely useless, and some of which are short essays, getting to every post would be absolutely impossible. I don't know what criteria Riot employees use to review posts, but I would bet that one of these are upvotes and number of comments. If a post is good, it will likely get a lot of attention. That's at least how I would do it.
I think it would be great if there was some way to directly submit a post to a Riot employee. There would definitely need to be some kind of limit to what can be submitted, and there would need to be an understanding that it could potentially take a very long time to get a response of any kind, if at all. This would be better for direct questions, and champion/item concepts. I've had a lot of those I've submitted that I would really like some professional feedback on, even if they were to ultimately tell me that my idea is total crap. I think a lot of people troll the forums just to shit all over people's ideas and downvote everything. And I still think that downvotes should not be allowed without a comment.