Tokyo Disneyland has a New Orleans Square (including a very similar copy of DL's Pirates and the associated facades, restaurants and shops). Though it's not considered a separate land, it's a part of Adventureland. Perhaps because unlike DL, it's JUST Pirates there, no connecting Haunted Mansion or Riverboat (or soon to be Tiana's ride) like at DL. So there might not be enough content for them to have classified it as a "full" land of its own. Not to mention that Pirates itself is acts as a sort of transitional ride into Adventureland even at Disneyland.
Transitioning into the Caribbean from a small New Orleans themed corner is a probably a fairly reasonable solution, especially compared to just leaving this stuff as-is. Provided they don't do it on the cheap. I would imagine they would leave the entrance archway into Adventureland alone (no reason to mess with it), but there's a decently long walkway with little there aside from the side of Pecos Bill and the Golden Oak Outpost concession stand. There's plenty they can do to aid the transition in that corner.