It's not really tautological - C++ is defined by the specification, adding things outside the specification make it not C++. What you're talking about here is not a trivial or safe alteration to the language, both examples are merely allowing previously disallowed syntax.

What you are suggesting is altering either the semantics of the language (no C++, including the STL, may define methods for foreign types, which include primitive/built-in types like arrays), or altering the contract between the compiler and the language (the implementation does not define any methods for primitive types, with the exception of a handful of things that must be implemented by the compiler, like sizeof).

Now I'm not saying its impossible for raw arrays to have nice features added in the future. Just that it's an uphill battle that has subtleties you're ignoring. It's not as simple as allowing some extra syntax that previously was disallowed.

Other stuff like forbidding coercion between arrays of the same type will never be added to the specification because it does more than allow new programs to be written, it results in old programs being forbidden. The last change I can recall doing this was the removal of auto_ptr and deprecation of some niche features dating to the 80s that no one actually used.