http://eel.is/c++draft/intro.execution#def:full-expression:

A full-expression is
— an invocation of a destructor generated at the end of the lifetime of an object other than a temporary object ([class.temporary]), or

Here is an example

void foo()
{
    const auto& rk = Klass{};
    Klass k;
    // ...
    // generated invocation `k.~Klass()` is a full-expression
    // generated invocation `rk.~Klass()` is not a full-expression?
}

I think it is intended to be a full-expression, so the Standard should say something like

other than a temporary object whose lifetime was not extended