The point of stem cell treatments is to replace cells that are no longer there doing their job. It's not too relevant for the replaced cells to be in the same spot, as long as they exist and produce insulin, you are good to go.
You could argue for the location having physiological implications, for instance: it's convenient for the liver to be right after the intestines (connected through the portal vein), like this, it metabolizes large amounts of whatever is absorbed intestinally at once, before it reaches systemic circulation.
This may hold true for the pancreas as well. It uses duodenal glucose concentrations to know exactly how much insulin to release, which may not be representative of the rest body's glucose concentrations.
Practically speaking, it is far safer to inject stem cells in the abdomen where you have room for erscqror and can do surgery on without much trouble vs the pancreas, if anything goes wrong there, you could easily kill a patient.
Autoimmune conditions can stem from viral infections, yes. But most of the time type-1 diabetics have a very weak phenotype of the disease, that is to say, the patient has pancreatic antibodies (specifically beta-cell antibodies) and produces them very, very slowly.
According to this source, half of all "new cases" (whatever that means) occurs in adults: https://diabetesjournals.org/care/article/44/11/2449/138477/...
You could argue for the location having physiological implications, for instance: it's convenient for the liver to be right after the intestines (connected through the portal vein), like this, it metabolizes large amounts of whatever is absorbed intestinally at once, before it reaches systemic circulation. This may hold true for the pancreas as well. It uses duodenal glucose concentrations to know exactly how much insulin to release, which may not be representative of the rest body's glucose concentrations. Practically speaking, it is far safer to inject stem cells in the abdomen where you have room for erscqror and can do surgery on without much trouble vs the pancreas, if anything goes wrong there, you could easily kill a patient.