>>53456518You don't need wormholes to explain gimmicks disappearing after each generation. After megas all the gimmicks they've done are lore-wise tied to the specific region the game is set in (for example in gen 9 terastalization is caused by energy coming from the great crater and tera orbs can only be made using crystals found in Area Zero, so it makes sense you can't use terastalization in other regions).
>>53456571Unova is specifically the area around New York, so it's less of a Pokemon world version of USA and more a version of one state, just like how Kanto is the Pokemon version of the real world Kanto region of Japan (we even see another region based on a US state later in Alola, which is based on Hawaii).
The "national dex" moniker is probably a leftover from when all the games were still set in regions based on Japan: thus you had the regional dex for Pokemon found in the specific region and national dex for all the Pokemon found in the nation of Japan (or its Pokemon world equivalent). It no longer makes much sense when from gen 5 onwards they started making regions based on other nations, but at that point the full pokedex with mons from all the games had already been called the national dex for 2 generations so the term was already established.
