It's probably just me being stupid, but how exactly does this help?
Well, it's not so stupid. I don't think that the 400 series packs have the camera serial number on them at all. They might have a pack serial, although I doubt it. These were shrink-wrapped packs, not fancy molded plastic ones. It's harder to mark the wrap, so they'd tend to keep it simple, I think.
They will have a pack mfgr's date code on them, though. Kodak would know what date codes were in what cameras, by camera serial number, and so would have given both pieces of data for a recall.
These days, you'll know, anyway. A pack that tended to pop it's caustic goo out the end will have done so by now. If it hasn't then it's not one to worry much about, even if the camera serial and pack date codes are in the proper range.
Unless, of course, someone runs across a new-in-the-box, never used unit. Even in this case, I bet that the pack is deader than a doornail, the aforementioned caustic goo having eaten away both the Nickle and the Cadmium from sitting for so long!
Heck, even the well-used cameras of this vintage probably will need a new pack, anyway. They're getting pretty old....