[over.match.ctor] says:

When objects of class type are direct-initialized, copy-initialized from an expression of the same or a derived class type ([dcl.init]), or default-initialized, overload resolution selects the constructor. For direct-initialization or default-initialization that is not in the context of copy-initialization, the candidate functions are all the constructors of the class of the object being initialized. For copy-initialization (including default initialization in the context of copy-initialization), the candidate functions are all the converting constructors ([class.conv.ctor]) of that class. The argument list is the expression-list or assignment-expression of the initializer.

Default-initialization invokes this clause with "the initializer ()" (see #2846) for class types. This clause has a similar issue.

The sentence "The argument list is the expression-list or assignment-expression of the initializer" uses the initializer grammar term:

initializer:

• brace-or-equal-initializer
• ( expression-list )

This does not accept ().

Thus, this clause has no ability to handle invoking a default constructor, such as default-initialization intends to invoke for class types.