Effects 11 is not supported by Windows Store apps for Windows 8.0 because it requires D3DCompile APIs at runtime. Hence, 'technique11' and it's kin are deprecated.
Effects 11 also has specific compiler support in the HLSL compiler, which in the latest (#47) is still there but emits a warning. Some newer DX 11.1 and DX 11.2 constructs are not supported with the legacy fx_5_0 profile.
All that said, you can technically use Effects 11 in a Windows Store app for Windows 8.1 because D3DCompiler #47 is present at runtime. You can also continue to use Effects 11 for Win32 desktop apps as long as you recognize a future HLSL compiler revision is likely to remove support for the required fx_5_0 profile.
See the Effects 11 CodePlex project.