Yeah it's just that Classic has the playerbase to allow for time to be invested in certain activities. Everything you can do on Classic, you can do on UN, but it's the fact that Classic is accessible to PC and mobile (allowing for more players) and being more popular overall inherently is why there seems to be more to do on Classic.
For those interested in adding to a discussion about a new kind of event system, I made a thread on it a while ago if anyone wants to check it out.