I call BS on this. I have never before heard the claim that Snap-on is discontinuing the Williams US tool production.
Where did you hear this claim? Do you have any links to prove it?
Until I see some proof I seriously doubt this. The industrial brands seem to keep US tools because that's what some of their customers want.
It's a logical conclusion I came to based on looking at what's more available in both the Williams catalog (socket offerings in 1/4", 3/8", and 1/2"; I don't need anything bigger) as well as online sites to purchase them from.
Another indication was in talking with a retailer that said their USA made tools were NOS, not current production.
Take a look at Amazon for example (searches):
1/4" socket set
3/8" socket set
1/2" socket set
Yes, there are still some USA items if you look through all of the pages, but I noticed that there were more Taiwanese made products. And this number has seemed to increase over time IIRC.
Seen this type of switching before (and been involved in it). It takes time, and the manufacturer may not admit it until it's done, as profits tend to be their ultimate guiding factor (might make a profit in the US, but if the profit will increase due to foreign manufacture, especially when it's a substantial increase, is an extremely tempting thing to resist from what I've seen).
As per customers wanting US made, that's fine (I'm one of them). But if it's not profitable enough to them, manufacturers will shift production elsewhere.
Even the US government will purchase foreign made products, including tools. Example's I'm directly familiar with, would be wire crimping tools from companies such as Thomas&Betts, Panduit, Tyco/AMP, and Molex (ODM's of their crimp tools are located in Sweden & Germany, as they make their terminals, but not the tools).