Yes, at first glance it looks like oxidation, but the far right edge of the picture does look like clearcoat failure. From this distance anyway...
It wouldn't hurt to try polishing it though, since at this point you don't have much to lose.
I don't think the part of metallic paints not oxidizing isn't really referring to metallic paints, but rather just clearcoated paints in general? :nixweiss I recall a discussion a long time ago that commented that clearcoat does not turn white and chalky like old single stage paints do, but it instead just turns dull and lifeless-looking. I know that is what happened to a silver van hood that belonged to my parents...