I've seen fake Apple chargers in local shops recently, with complete Apple packaging, "made by Apple in California" etc. and only detectable by close inspection of the details, specs not matching any Apple product, device info reported electronically that doesn't match any Apple specs, and the tiny inset writing not making sense when looked at under magnification. So that sounds plausible to me.
If you do that, you're losing grounding, which will result in the machine having that AC leakage buzz when you touch it. The chrome lug that the plug nub slides onto is a ground connection, and the Apple official cords and some country-specific nubs implement the ground brush connector. There is (was?) a third-party Schuko (not Europlug) nub.
Those power supplies often shipped with both a full cord input which was grounded but also a folding two-prong component that made it in to a wall wart and of course was not grounded.
So in this universe Apple doesn't invent its own standards...