Very much doubt that, ordering a different steel or heat treatment is so much cheaper than moving production, especially if existing production remains in Spain. I think Snap On just planned to make them in the US, and doubt the previous Spanish made were subpar in any way. Such rumors only started spreading after they started making them in the US, but I don't think there were any complaints while they only sold the Spanish versions.
Torque Test Channel, if I’m not mistaken, did the video were at least on of the Spanish made Irimo produced wrenches was found to be way softer than expected.
My experience with Bahco branded, Irimo produced wrenches, was that the dynamic jaws were sometimes offset due to poor machining.
Years ago, there was at least one post about a Snap-On branded, Spanish made adjustable wrench, that also had machining issues.
Since Bahco and Itimo are both part of “Snap-On Europe” the wrenches are almost certainly made by one of the Snap-On tool facilities in Spain, and quality problems seem to be ongoing with the adjustable wrenches.
The Chinese made Crescent branded wrenches came out better than the Spanish Irimo wrenches in one of the Torque Test Channel videos as well. (Maybe the same video that found hardness issues.
Non of these issues supposedly existed back when the adjustable wrenches were made in Sweden.
As fir the older US made Crescent wrenches, the steel might have bern good, but the machining was far from tight in the later years.
Western Forge wrenches usually had pretty hood machining, as far as tightness, although I’ve never used mine for abusive torque tests.