That seems likely, especially with there being no other elder subspecies to break out without introducing a new-to-World monster like Fatalis or Lao. I'm actually shocked that after all this time there's been no subspecies for Teo and Luna in the mainline games, but considering how much every person on the planet hates Luna in particular, that may be for the best!Given that it's a alternate version of a monster already in the game, I could see another 2-for update with Oroshi Kirin and another alternative version (probably Rusted Kushala).
I do feel like we'll see Molten Tigrex sooner or later.