In theory, and this is another couple of major advancements of this tech away, if you can teach the body to stop attacking specific cells you can do a transplant without rejection. Teach the body to not attack the new pancreas, then stick it in there.

This should be possible with this tech, though it would require a mature and advanced process compared to what we have now. Genetic chimeras can exist without the immune system going crazy, presumably because it recognizes all those parts as "part of the body". If it can be taught to recognize other implanted material as acceptable that opens up a huge range of options. Even a lifetime of immune system training therapy is better than a lifetime of immunosuppressants.