Oh dear... this news isn't really unexpected unless you don't understand national infrastructure planning approvals.
The announcement today just outlines the process to be followed by HMG.
Once they announce their preferred option, it consults on it, then publishes a National Policy Statement, which then needs to be approved by Parliament "next winter". Heathrow would only then apply for planning permission under the framework (& support) of Government policy.
I believe the AC set out this planning route so it should've been expected.