The names of all the pickups are directed more at the overall vibe rather than one specific tone or point in time.
Mother's Milk spec is essentially a mid '60s spec, 42 AWG plain enamel wire and Alnico V magnets............the real tweak is the slightly hotter bridge which is done for balance and to releave broken glass that alot of Strats suffer from in the bridge dept.
John's tone has changed alot although it's probably as much to do with different recording, producers etc as different guitars.On the whole he seems to favour stock vintage guitars.
For some players, you mention Strat tone and they picture Hendrix, some Marvin, some SRV.............for me it's always been the Chilli's. I hear so many of the different Strat tones in their music hence the association.
I would never like to make a pickup and tie someone down with it's tone and say that'll make you sound like Frusciante but that's all it'll do.I'm trying to produce pickups that'll take you somewhere, a vibe, where you'll feel inspired and use it as a building block to create your own palette of tone.
Oh, and I thought it was a cool name too :D