No, not entirely true. AVRI JM pickups are like the originals, black bobbins same size as originals and wound in a similar manner.djetz wrote: I've heard that the Fender JM re-issue pickups are actually strat-type pickups in JM covers, rather than actual JM type pickups.
What you may have heard is regarding MIJ/CIJ JM pickups; The inner part of the bobbin is much narrower than original and they are not wound all the way to the outside of the bobbin, making the actual magnetic field more the size of a Strat pickup than a JM (although the pickup itself looks like a JM pickup).
Hope this helps...