223201
I'm in the same boat, Hoenn. Or at least, I always forget.
But the change does work for a nice bit of balancing, and it makes sense as well. After all, what is magma without fire, really? Dirt? (That said, this change does make Kyogre more of a threat, I really don't see why Aqua has trouble with Magma). Though...when you think about it, this makes a lot more sense in terms of lore. If it were just Ground, the whole "Groudon and Kyogre create Continents" deal wouldn't really make sense considering there's no real duality between Earth and water and, in a real life sense, water and ground would basically simply lead to corrosion, as opposed to Fire and Water (or Lava/Magma and Water), which actually create land.
...Though I guess if one were to argue Earthquake it could work out, but even then, no real need for duality.