Rationale (February, 2021):

The text in question no longer appears in the Standard.

Although 14.5 [except.spec] paragraph 3 says,

Two exception-specifications are compatible if:

• ...

• both have the form noexcept(constant-expression) and the constant-expressions are equivalent, or

• ...

it is not clear whether “equivalent” in this context should be taken as a reference to the definition of equivalent given in 13.7.7.2 [temp.over.link] paragraph 5:

Two expressions involving template parameters are considered equivalent if two function definitions containing the expressions would satisfy the one definition rule (6.3 [basic.def.odr]), except that the tokens used to name the template parameters may differ as long as a token used to name a template parameter in one expression is replaced by another token that names the same template parameter in the other expression.

since the context there is expressions that appear in function template parameters and return types.

There is implementation variance on this question.