Title says it all. In an unevaluated context, the result is never used anyways. Other compilers do ignore [[nodiscard]] in those contexts already. Example code:

struct A
{
    [[nodiscard]] static int match() { return 42; }
};

template<typename T>
auto g() -> decltype( T::match(), bool() )
{
    return T::match();
}

int main()
{
    g<A>();
}

Leads to:

<source>: In substitution of 'template<class T> decltype ((T::match(), bool())) g() [with T = A]':

<source>:14:10:   required from here

<source>:7:31: warning: ignoring return value of 'static int A::match()', declared with attribute nodiscard [-Wunused-result]

    7 | auto g() -> decltype( T::match(), bool() )

      |                       ~~~~~~~~^~

<source>:3:30: note: declared here

    3 |     [[nodiscard]] static int match() { return 42; }

      |                              ^~~~~

Compiler returned: 0

See https://godbolt.org/z/OQEnaD