I have been reading that same crock of nonsense off and on for 60 years. It is just one of those myths/old wives tales that somebody puts in print and somebody else repeats it and so on and so on. Even gun writers and load book editors who should know better are not exempt from this kind of stuff. Folks without experience read it and will swear it is true because so and so said it or they read it in such and such, when it fact it has never been true.
The 32 WS offers a smidge more power than the 30 WCF and some folks might think that is important. However any critter done in with one or the other won't know which one did the deed. As to a 32 caliber 1-16 twist barrel wearing out sooner than a 30 caliber 1-12 twist barrel that is just utter nonsense. Yet folks who don't know better, will swear it is true because they read it somewhere. This should not surprise anybody because there are folks who still think the earth is flat and man descended from monkeys.
The genesis of this notion seems to come front another myth about the 32WS which is it was designed for folks to shoot black powder if they wanted and the rifling was shallow to keep the barrel shooting when fouled with black powder. Therefore the shallow rifling would wear out quickly and bullets would rattle down the barrel. Neither of these assertions which comprise the foundation of the aforementioned myth are true.
Winchester designed the 32 WS to shoe horn some more power into the 94 platform. The buyer would have to step up to the 95 to get more power and many did not want to do that because the 95 cost more and was heavier to tote in the woods. In short Winchester though they could sell more rifles with the 32 WS added to the 94 lineup.
Whatever was the reasoning of Winchester, for us cast bullet levergun loonies, latching on to a good 32 WS is like finding the pot of gold at the end of the rainbow.
The 30 WCF was always going to be the favorite because it was a 30 caliber. The US military first adopted the 30 Army (30-40), then the 30-06, the 30 Carbine and the 7.62. This love affair between the military and the 30 caliber was guaranteed sales to civilians of 30 caliber rifles.
Here is a link to a good article about the round written by Mic McPherson. I consider this to be definitive.
http://www.levergun.com/articles/special.htm