Given that the list of serial numbers are non-consecutive (and one of them in a run of consecutive numbers went to a vendor in Austria per the article linked elsewhere in the comments), perhaps they're only recalling the ones that went to Europe where the regulation is in place?

The f6 is high end low volume product. They only make and sell a couple hundred a year.

Looks like it costs $2,549. Which doesn't really seem profitable in volumes that low.

Nikon and Canon's pro SLR ranges are product ecosystems with massive switching costs. They maintain all sorts of products and services that don't make economic sense in isolation, but are necessary to maintain a comprehensive product ecosystem. A professional or serious amateur might own tens of thousands of dollars worth of camera bodies, lenses and accessories; for a small but meaningful proportion of those customers, the continued availability of the F6 will be the key factor in their choice of camera system.

It's quite mechanically and electronically simple, though, by modern standards.

And some of the more complicated or precision components (shutter, mirror, viewfinder screen + prism, lens mount, autofocus motor, autofocus and autoexposure sensors) exist in similar forms on newer products and may be able to share production lines to some extent.