It's not hard to figure out, but every time they do something like that they kill a bunch of builds the same time they intend to introduce a lot of new ones.
EX: When they split physical and special Sceptile got its Leaf Blade build hit hard because it has high special attack.
It's probably worse in this case because the physical/special split was splitting into two different types whereas this time they're making two different properties split between 19 types, meaning moves can have up to 361 different combinations of properties. Combining with that that only a handful of moves are actually useful, the system would only add a lot of interesting aspects to gameplay if they plan on adding thousands of new attacks, which probably won't happen.
Though I guess the other option is to make said kinds of attacks very sparse so that they are only viable for special builds of Pokemon.