IIRC it was never a case of CuNiFe being unobtainable in an absolute sense, just that it was too expensive to be practical. Big companies focused on maximising profits didn't want to pay for gigantic orders of 'em and since the big companies weren't bothering, the price for small orders also went up to the point smaller companies simply couldn't afford to use it, either, so then the factories just stopped offering it.
What I would guess has happened, having had a bit of insight into Fender's product designing process a couple of years ago, is the premium electric guitar market has become niche enough—overall sales down, but the people that are buying guitars want them at a higher quality and more specialised than before—so it has once again become worthwhile for a company like Fender to buy in a few big lots of these magnets in order to produce a specific model for a year or two.
FWIW I've A/Bd some original 1970s Wide Range humbuckers alongside some AlNiCo-based recreations from a couple of companies, in the same guitar body, and for the life of me I couldn't tell the difference. Especially with The Creamery's recreations. The technical specs under the hood may not match but the tone and response you get as the end result is identical. It's nice Fender have gotten the 'real' thing back in some form, but don't expect any kind of revelation in sound.
