No, it never was true, even for R12.
The watermelon party dreamed up this scam to undermine the AC industry. Dupont didn't quite have the corner of the market on refrigerant, so they joined forces with the moonbats in their lobbying efforts, and got it banned.
Then they came up with a "new refrigerant" (R134) and consequently were now its only producers.
hey when the protected folks patents are about to run out ya gotta get something new passed doncha know