One of the things that I really do love about hive is that there are many places that are focused on community. Splinterlands as you mentioned does an excellent job giving people things to engage with. The 3 weekly contests def keep things lively. Obviously there's only so much you can do when the game isn't launched yet but I m sure once Holozing launches you'll keep up the awesome work.
Really the key thing is that Hive was built for the long term.