Most likely not possible (but i can dream) Even if its rough, not good transitioning i feel like it could be a cool idea playing survival or multiplayer could be cool and a total pain at the same time.
Much more rare items could be kept in bases making finding a base to raid much more rewarding. All the maps would be just like they are individually so per map strategies for collecting loot could be used so some maps would be less of an intrest point (Yukon for example) even if the player limit was brought to 48 like some servers have it.
Well its not like we know for sure the unturned earth is the same as irl, and im pretty sure some maps/countries that arent even near each other have borders and lore in game so it could happen.
Some positive things this could bring. Players would not be short of cars since respawning would have a large chance to bring you to an unexplored area (a limit of how many one person can lock should be introduced just in case). Maps could be updated with new lore and changes only found in the combined map making playing there a totally new expierience. Perhaps even make lore locked items (the best guns you get all come broken, not 0% but just not working and you need to find the military codes for a bunker to find thier scematics and components that you need to fix them, idk). The map could be made more survival like (lower loot spawns to encourage exploring, since there would be a lot of places to explore).
Negatives could be dividing the playerbase, but most of the people who wouldnt play a map like that are unskilled players on x loot servers so its not that likely it would happen to a large extent