R-12 A/C refrigerant in 1994 Suburban

[AutoandHVACnut]

I came across a traded-in 1994 Chevrolet S10 Blazer on a car dealer back lot last Spring, and I was surprised when I popped the hood to find that it had come from the factory with R-12 (or Freon, Freon-12, CFC-12, etc). It had been converted to R134a, but it still had the original labels on the compressor and on the firewall next to the accumulator, indicating that it had originally had R-12. The reason this 1994 model year Blazer probably got away with having R-12 is because it was manufactured in October 1993 which was before all of the Montreal Protocol and Clean Air Act regulations took effect. I have heard rumors that some 1994 vehicles manufactured as late as mid-1994 and even a few early 1995 vehicles had R-12, but it isn't that common. I looked under the hood of a 1994 Ford E-series van manufactured in September 1993, and it came from the factory with R134a. It had big-lettered warnings not to use R-12 because it would damage the system. I also saw a 1993 Mercedes S-class on eBay that had been manufactured in late 1992. It had highly detailed photos including some of the labels under the hood, including the air-conditioner info. The factory label indicated that this Mercedes manufactured in 1992 came form the factory with R134a. The question I am asking is this: Is it possible that 1994 model year Suburbans, Blazers/Yukons, and C/K pickups/Sierras manufactured in late 1993 or very early 1994 could have come from the factory with R-12 before the mandates took effect?