While R-134a's use in new cars is now banned (new cars now use R-1234yf), there are millions of cars and trucks still on the road that will require R-134a refrigerant for service. What may happen is in the future, anyone looking to purchase 134a will have to show they've received training on refrigerant handing and recovery. This is similar to what took place when R-12 was banned in the 1990s. The new R-1234yf refrigerant is NOT compatible for use in R-134a systems. The reason for the switch to 1234yf is it has a much lower global warming potential than R-134a. Both 1234yf and 134a do not deplete the ozone layer, which was the chief concern with R-12.
Per the EPA website: "Servicing of existing vehicles using HFC-134a with HFC-134a will not be impacted and will continue to be allowed."
https://www.epa.gov/mvac/refrigerant-transition-environmental-impacts
So I don't think you need to rush out and buy a case of 134a. When the EPA mandated the phase-out of R-12 in the 1990s, a slew of mostly bad replacement refrigerants hit the market, which ended up biting many car owners and shops in the butt. Hopefully the EPA learned its lesson from that debacle and will not make the same mistake twice.
Speaking of R-12 refrigerant, I turned in 5 one pound cans of R-12 to a household hazmat collection site the county was running a few weeks ago. I discovered them in one of my toolboxes. When I left auto mechanics in 1995, I hoarded a couple of cases of R-12 for my cars, so that is how they came to be in my possession. Before I turned them in, I took a look at eBay Motors and was shocked to find listings for R-12 refrigerant. I was not about to give or sell them to someone I was not sure would handle this refrigerant properly.
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