But the Neumann and ART1000 both have cantilevers wafting around upon which the coils are mounted
The diagrams I have seen of the Decca moving iron (MI) cartridge do label the structure holding the diamond stylus as a cantilever. It is different in shape and position from typical straight cantilevers, though, and is made of iron.
Essentially it runs nearly vertically above the stylus, before doing a near right-angled turn towards the rear of the cartridge, where it is flattened into a flat spring shape and clamped in place. The spring allows the stylus to move vertically through bending, and sideways through twisting (with different compliances!).
On its own, this (double?) cantilever does not prevent some unwanted fore-and-aft movement of the stylus, so a tie-back cord is added where a more conventional cantilever would run. The actual cantilever is hidden above the lateral coil and magnet structure.
Have I got this right so far? For the diagrams I am looking at, see for example Those Were The Days:Ortofon A/B, SPU, Decca London, Garrard GMC and Tannoy VariTwin Phono Cartridges
These diagrams also show damping medium (rubber?) attached to the flattened spring.
I don't think it is fair to suggest the ART1000 has its coils mounted to a cantilever which wafts around! The coils are mounted almost exactly over the stylus as can been seen here Direct Power Stereo MC Cartridge | AT-ART1000x | Audio-Technica | Audio-Technica. The cantilever exists solely to position the stylus in the body, and to stop it rotating.

