@Andrew Kutscher Your friend is getting hosed. While R-22 is no longer being produced as of 1/1/2020, there is still plenty of it available. Legally, it can still be sold, they just cant make it anymore.
In regards to his home warranty, an R-22 system works exactly the same way as a R-410A system (R-410a is the refrigerant that replaced R-22). It is not completely different. In fact, manufactures have not been able to build systems that use R-22 since 2010, so this is not a "new" thing. He needs to speak to someone with a little more knowledge at his warranty company.
Yes, if you have an old HVAC unit, when you replace it, you will have to use the new refrigerant. As I said, this has been standard practice for the last 10 years already. I personally know of hundreds of cases where a home warranty paid for a new system that utilized the new refrigerant.
Be careful of where you get your information from. Your link is from an HVAC companies blog post. There is some misinformation in there. Certainly their goal is to drive people into purchasing new equipment. Equipment replacement is typically driven by what the cost would be to repair it vs replace it. As the R-22 supply drops the price goes up, so it becomes more reasonable to replace vs. repair.
For accurate information, check out this link from the EPA.
https://www.epa.gov/sites/prod...