2023 D Major struck thru grease shield cent

Yes, they do. It’s not the zinc that work hardens . . . It’s the copper.

 

The copper layer is 20 microns thick. No matter . . . it’s the outer layer of the coin under greatest stress, so yes, annealing of the copper is desirable to promote it stretching without cracking when struck.

 

I don't think the design and pairing of the dies had much to do with the appearance of the OP's coin.

If dies were poorly designed, you likely would likely not find coins fully executed side-to-side among all coins of this design, instead finding some areas of the coin well-struck, and other areas consistently lacking in detail.

The dull look of this coin points further toward a rare event affecting the outcome. If all steps in the normal minting procedure were followed, the coin would be brighter and more lustrous than it is, and hydraulic presses in normal production runs would ensure that virtually the same level of design detail was imparted upon all normally prepared planchets.

Finally, if poor design, manufacture and / or pairing of dies were responsible for the appearance of the OP's coin, a much larger number of such examples would have been found.