Bit of a quibble but I'm not sure I'd call that a "huge breaking change" given that that feature wasn't really implemented in the first place, let alone actually used.
It was a bad feature, as the two main C++ commercial products that make use of GC, namely C++/CLI and Unreal C++, were never taken into account while designing it, a good example how WG21 often does PDF driven design.
https://cppreference.com/w/cpp/compiler_support/11.html
It was a bad feature, as the two main C++ commercial products that make use of GC, namely C++/CLI and Unreal C++, were never taken into account while designing it, a good example how WG21 often does PDF driven design.