Setting -ZW option in pro file with winphone build is overridden by default when exported as visual studio project

Simple project with:

QMAKE_CXXFLAGS += -ZW

When exported as vs project:

qmake -tp vc ...

CompileAsWinRT is always false (but not with win32 projects). Seems the default set to false by commit fc5e948ea8b2f9b54c3468d32f7e04f92d247567. With my limited understanding of winrt and such, I don't know if this option should be false in this case or if it should override one set in .pro file. How ever, this option can be enabled through visual studio project settings and code can contain C++/CX code after this is set.