Does the Rune/Mastery revamp mean I can't mix/match on offence/defence any more?

Right now I usually go for an aggressive Mastery page that scales a bit, while taking heavy armor rune pages often because of both my lane and the jungle being AD and how snowbally the gamestate currently is.

I love the utility of Zombie wards. But I am afraid that a couple of big choices, as they say, will actually hurt my options. And create a couple of distinct playstyle around certain runes, with champions that don't fit them being left behind.

The current Mastery system with keystones has already done this a fair bunch. Ask anyone who experienced both. And it seems they are digging in.