Ark does indeed use UE4, but my below comments are mostly meant to respond to both yourself and CodeMage. TLDR: It’s not a UE4 limitation, it’s a limitation of server, development, and architecture resources. Just because it’s not a UE4 limitation doesn’t mean there aren’t valid technical reasons why FunCom didn’t connect the maps.
This. Also it is important for players to understand that most development studios have to add their own code and tools to any engine they use (or they have their own proprietary engine). This means that even though Ark and Conan Use UE4, they both use different versions of the engine with different modifications.
In essence, they are completely different Game Engines sharing a common core. How different the engine versions are is an important (but far from the only) factor in how difficult it is to migrate a project from one engine to another.