Thanks for your kind words!
Subsequent hives are only connected through your imagination and the continuity of your lineage of Queens. It's a way for players who enjoy the early part of the game "start again" without feeling like they have to quit or abandon their game. Research stays unlocked (but building requirements are still present - you still need an Updateded Workshop before you build a Barracks, etc.), so you also have an opportunity to build and design new hives in a way that you wouldn't be able to for a first hive.
In future updates, there will be some content that won't appear until multiple hives have been created.
Hope that helps!