There is a group of folks based in the UK, who call themselves the Insulin Dependent Diabetes Trust, who have been championing continued availability for animal-source insulin products. I'd suggest the interested reader go to their website, and review their arguments about insulin choices. They also list animal-sourced insulins that are still available.
But will animal-sourced insulin products come back to the United States? No. Like buggy whips, there's just not enough demand for the product. The newer stuff is both better and cheaper. What else could the average patient want?

