Version Used: Version 16.6.0 Preview 2.0 (master) (private branch build with unrelated changes)

Steps to Reproduce:

enum E { A, B }

class C
{
    bool M(int i)
    {
        return (E)i switch
        //     ~~~ IDE0004 cast is redundant
        {
            E.A => true,
            _ => false
        };
    }
}

Expected Behavior:

Cast is not flagged as redundant.

Actual Behavior:

Cast is flagged as redundant. Removing it introduces CS0266 on E.A in switch case.