Enable Rioters to show their appreciation for threads
Ghostcrawler replied in his "balance" thread
That's a reasonable concern. My personal experience from a decade and a half of trying to communicate to players is that if you step into a good discussion, you risk derailing it. Devs can still read and appreciate the discussion, and we do, but if we try to "reward" the thread with our appearance, it ends up attracting a lot of folks who want to make "Rito where" posts or troll or whatever. Troll threads are in essence already ruined, so a dev jumping in can't make it much worse.
Maybe you can find a way to award posts/threads that the developers found helpful in some other way than actually posting a reply. Just put a "stamp of approval" on it, maybe even so it's identifiable who of the devs put his stamp on it, although that might have negative effects similar to what was described, like "ermahgerd, only lowlevel devs here, ghostcrawler doesn't give a hoot!".
Doing so might still kind of derail discussions because people might start to chime in just because they know the thread is being looked at, so maybe make the stamp visible only to participants of the thread? Or allow both options, giving people a personal incentive to keep the discussion flowing first by showing them that their thoughts are being recognized, and when a topic is about to dry out, get a public stamp on so others can look at what is helpful feedback.