Incorrect.

TdF introduced in 1948 and made throughout the 50s.

GS introduced in 1951 and made throughout the 50s.

Same era. Unless of course you think 3 years constitutes an era.

Also, for the third time, the problem with this type of derailleur is the pull-chain and coil spring directly moving the jockey cage side to side. It is a horrible setup. When shifting by the cable pulling on the chain, it translates that force by nearly 90 degrees against the force of the coil spring to move the chain. That 90 degree shift in force causes the whole derailleur to torque which then twists the chain across the cogs. It makes for a loud and sloppy shift. Now maybe with a new derailleur with no wear, the twisting doesn't occur, but my TdF is nowhere near NOS.

With the parallelogram of the GS on the otherhand, the cable is pulling on on the derailleur body instead of directly on the jockey wheels. The torque created is actually supposed to "twist" the deraileur body. But in the case of the GS, the jockey cage stays parallel to the cogs for a smooth, quiet shift. Sure, I may have to overshift a bit but it is nonetheless an easier shift.