Well, I see this "problem" still has a lot of people worked up, so I checked every OEM top end kit I have in stock here for SWP syndrome. (sliding wrist pin). 25-30 kits in all.
Models are: 372, 372XPW, 272, 288, 357, 562, 550, 55, 365, 372XT, 390, 395, 254, and 262. (the last 2 aren't for sale; don't even ask.

) Multiples of a lot of the kits, especially the 372 based kits. Every kit has the wrist pin installed in the piston. Nearly all of the wrist pins are nice and tight and would not move. Only one kit "failed" the shake test and made the "ding, ding, ding" noise. And that particular cylinder shows no signs of damage. (It was one of the five 372XPW kits I have; the other 4 were fine.)
So, is this really a packaging problem, or maybe a small inconsistency in the wrist pins, or maybe even the ID on the piston?