"I don't have any reference material at hand, so I'm not sure if the .38-40 and .32-20 were also produced in a hi-speed loading or not."
Possibly other Winchester black powder cartridges that made the transition to smokeless, as well.
The loadings were discontinued because, the same as today, idiots wouldn't read the warnings on the box and were loading them into Model 1873 rifles or early Model 1873 Colt revolvers.
The rifles tended to lose their side plates, and the revolvers tended to either stretch the hell out of the frame, or crack the cylinder.
HERE we go! A vintage Winchester .32-20 box with the warnings clearly printed in red!
Winchester High Velocity .32-20
Cartridges so manufactured by Winchester (Note that the factory term was High Velocity, Hi-Speed was a Remington mark) were headstamped WHV