Hmm, I think more thought needs to be put into this idea.
Suppose a new nation joins up and requests a land stake in the region formerly owned by Nordic and Nephele. If either of the two are revived, that new nation would be robbed of his/her land stake.
Considering that the new nation would have no idea about the former occupation, and that the former nation had essentially "quit" the game (hence validating their removal from the map), would it be fair for the new nation that we gave preferential treatment to the quitter?
In my opinion, the quitter quit, so by law of respawn, he/she must start anew and ask for a new land claim. (<-- this is not my new rule, just my opinion).
If we kept a record of past occupations to guide future occupations, that would defeat the purpose of having removed the nations in the first place. May as well have just left the inactive nations there so that no new nation claims the land.
That said, the only viable solution I can think of is if we only allow existing, adjacent nations to fill up the vacuum left by the former nation. On a role-playing scale, this would be like having the weaker nation get absorbed into the stronger nation(s). Problem is we may get one nation that ends up taking up a ton of land.
In the case of the Nordic/Nephele region the land would have to be taken up by Akryo and possibly Podsixia. Assuming an even split in the land, Akryo and Podsixia would become one of the largest nations by land acreage. Otherwise, if either refuse, the sole nation would become THE largest. If both refuse, then the region becomes a no-man's land and a waste of space.
Let's do some more thinking about this, ladies and gentleman. Think about the consequences of your idea. Is this even an issue worth pursuing?
Map update
Glaviel expanded.