Yes I think they might, but like you said the ports need to be more than just pay-upfront versions of an otherwise identical mobile game.

If you actually watch trailers for Monster Strike you can see that there is a full-fledged 3D RPG here. The mobile-style battle system has been retained but it really looks like the developer sunk time and money into making a proper 3DS game that you're just not going to find on smartphones. I think it's a great idea to port super popular mobile games in Japan to the 3DS in this manner because the serious/non-casual fans of the mobile game are going to be inherently attracted to the more immersive game experience that is available on the 3DS. The mobile game almost becomes its own sales pitch for the more fleshed out 3DS title.

Nintendo might be well-advised to take a hint here for when they start releasing their own mobile games: a trimmed down version of a Pokémon or Yokai Watch game that focuses in on one part of the game (like the battle system) could make for a great mobile game, save on development time and serve as a huge sales pitch for buying a Nintendo handheld!