Come on the Next A+ will be at Pi3 speeds and have a removable WiFi, I don't know if the 'Cavity' can technically be removed, but it would need to be able to disconnect.
Also there is no reason the design has not changed since it's first inception.
They've pretty much managed to redesign the Zero twice in that time, one of the advantages of having the Sony Wales site I guess.
It's just shuffling things around* not a completely new concept design. They already had the basics for it.
It needs to have everything at the top end, so end customers can have it designed lesser as they need. Slower clock, yep done.
No WiFi or BT, yep taken out etc.
Anyways await and see.
Ebon stated around the ZeroW launch time(MagPi/some other site quoting) they on with the software of education march now and only small itteretions if needed in the hardware.
I guess some stability in the Pi's for a while, but needs will decide.
*I make it sound easy
(I've bought a nice Pimeroni ZeroW project kit for my son's birthday)