I literally worked in a research lab working on islet cell therapies for diabetes in the US. This has actually been done many times before with cells from cadavers. It has been successful, although most the of the time the person reverts back after a few years because installing in the hep

The issues we were trying to solve in the lab were

Finding a good place to transplant where the cells will last: Implanting in the hepatic region (liver), which is the most common place to implant, is toxic to the cells over time hence only lasting 3-5 years. The cells need a really good blood supply and the volume you’re transplanting can’t be easily transplantes in the pancreas or kidney capsules (where many successful studies were performed in mice and rats)

Being able to consistently make a high volume of stem cells that are fully grown into insulin producing cells: Cadaver cells usually require 3-5 donors for 1 person and require the receiver to be on lifelong immunosuppresors due to the immune response. Depending on the kind of stem cells, the patient may still even need immunosuppresors due to the cell type you’re converting from

All this the say - the article says nothing about where the cells where transplanted, where they came from, or whether the person has Type 1 or Type 2 diabetes. Although it is still a feat, it is likely not the first time it has been done, and we’re still a long ways off from a cure

"The new therapy involves programming the patient's peripheral blood mononuclear cells, transforming them into "seed cells" to recreate pancreatic islet tissue in an artificial environment."

I don't see anything for the other two questions though but being patient derived would seem to fix your number 2.

Unfortunately, that doesn’t necessarily negate the requirement for immunosuppresors or some other kind of immuno protection. If it is Type 1 diabetes, the person originally became diabetic because the immune system saw certain markers on the beta cells (insulin producing cells) as a threat. So, if you recreate the beta cells, there is still a possibility that it will happen again. You are fighting your own immune system. Someone in our lab was studying encapsulation of cells to create a protective barrier around them for this very issue

If the person was Type 2, this might be less of a risk since type 2 can also be due to high insulin resistivity. There are a lot of other factors involved, though, it’s not straightforward