The copyright holder can set whatever license they want, including writing their own.
In this case, I'd interpret it as they made up a new licence based on MIT, but their addendum makes it non-MIT, but something else. I agree with what others said; this "new" license has internal conflicts.
In this case, I'd interpret it as they made up a new licence based on MIT, but their addendum makes it non-MIT, but something else. I agree with what others said; this "new" license has internal conflicts.