You can still beat Go using "simpler" math. If you have enough compute power, you can always just minimax the whole game tree. Neural networks aren't un-mathematical; they're just a slightly more complicated technique for discovering an approximation to a function that does what you want (even if you're not sure what that function looks like internally).
So AlphaGo's reign will last only until QuantumGo arrives on the scene? It would be sort of ironic to have spent decades developing practical AIs with classical computing to have them swept aside only when they started to really deliver results...