And then for the legal part, that's why it's called an exception.
And again, where is the interoperability here? Interoperability exception would apply if there was whitebox cryptography, Nintendo logo-style things or anything else where the only method for the work to run would be to violate copyright of _exactly that_. Under no circumstances you can simply copy & distribute the entire work (or derivates) while claiming "interoperability exception!". It makes utterly no sense.
And then for the interoperability, these decompilation projects are primarily made to target other systems, not the original platform. That's the textbook definition of interoperability.
Let's be real, N64 and the PS1/PS2 (where most of these projects are based) are crumbling old platforms at this point and these projects are sometimes the best way to run games when they exist.