According to the files I examined in Bundesarchiv, the following happened. This is of course not a neutral description, because it is solely based on the opinions of the members of the German proof council.
The .38 Special Wadcutter as a separate cartridge definition came into being due to the creation of automatic pistols in .38 Special for match shooting. These could only be loaded with Wacutter cartridges [not explained why, I presume magazine dimensions]. Therefore it was considered safe to create a cartridge named .38 Wadcutter with a lower maximum pressure (80 percent or 1200 versus 1500 bar). The pistols were designed for the weaker Match loads, so it was thought a good idea to create a special proof load for them.
The .32 S&W long Wadcutter is an entirely different story. The .32 S&W long caliber became very popular for UIT (today ISSF) shooting because it was a “fullbore” cartridge under UIT rules with practically no recoil compared to real life fullbore. Pressure was only 1000 bar (approx 14500 psi).
The Liege proof house at some time [must have been before 1984] approved a cartridge with the same case dimensions, which was called .32 S&W long Wadcutter with a maximum pressure of 2200 bar. This catridge was finally accepted by the CIP plenary session “at London”. Today its pressure is set at 1550 bar.
Normally, a cartridge called “(semi-)wadcutter” will be assumed to be less powerful. Whatever the reasons were, assigning .32 S&W Wadcutter a pressure considerably higher than the proof load of the ordinary cartridge does not seem a good idea. Anyone owning a .32 S&W long revolver (or .32 Colt New Police) may be tempted to fire .32 S&W Wadcutter, which is most dangerous.
So the “homologation” of .32 S&W Wadcutter has in my view to be considered a black day in CIP history as an organization founded for firearms safety.
In the CIP database, the origin of this cartridge is given das Germany/Finland. It would be very interesting to find out more details. Because it was the executive director of Walther (GSP pistol!) who initiated the complaints and considering Walther’s close cooperation with RWS/Geco, I have no idea who in Germany could have proposed this dangerous cartridge.