TFA claims the stem cells were administered into the abdominal muscles, which may reduce the "significant risk of stem cell transplant" compared to direct injection into the liver.

I'm curious why they don't transplant into the pancreas?

Stem cells are pretty good at moving around. If they don't want to stay in the pancreas, you won't be able to make them, and if they want to go to the pancreas, they will find their way there even if transplanted in a less invasive way.

How do stem cells move?

It seems from the article that it's harder to monitor, so by injecting in the abdomen they can monitor them using MRI and remove them if needed.

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.

I’m surprised more people didn’t try that route earlier. Step one in stem cell transplant for leukemia it to kill all existing immune cells. HIV hides in immune cells.

I think too many HIV patients were too compromised by opportunistic infections to ever be healthy enough for stem cell transplants

Nowadays many hiv positive individuals are in better than average health. And a fluke for the ones diagnosed with AIDS they enjoy a slightly longer than average lufe expectancy. This is part a survivor bias, where only the fittest of tgat cohort survived. It is also due to their being eledgable for medicaid with double the income of anyone else.