Proposed resolution (approved by CWG 2023-04-28):

Change in 9.5.1 [dcl.init.general] paragraph 13 as follows:

If the entity being initialized does not have class or array type, the expression-list in a parenthesized initializer shall be a single expression.

[Accepted as a DR at the June, 2023 meeting.]

Consider:

  const int arr[2](1,2);

This is accepted by all major implementations, yet 9.5.1 [dcl.init.general] paragraph 13 prohibits it:

If the entity being initialized does not have class type, the expression-list in a parenthesized initializer shall be a single expression.

Presumably, this was an oversight when adding parenthesized aggregate initialization.