It is wonderful that your husband has recovered after you made the dietary changes. Your observations probably are perfectly valid in his case. However, extrapolating from a study with n=1 to an entire population may not be justified. For one thing, individual people have unique sensitivities. If your findings were generalizable you have to ask why I and a lot of people don’t all have Type 1. I eat all the “bad” stuff. P.S. Best wishes to your husband and yourself.
I think our experience with diabetes is simply to hammer home the idea that its a very complicated condition. A “one size fits all” summary is not correct. I’m of the (there’s that word again) “belief” that diabetes is actually a food allergy - hence the difficulties in quantifying it. Some people like my husband may have developed the allergy while eating foods laced with high Fructose Corn Syrup, others, eating genetically modified soy. Much of the diet foods out there do not satiate and actually cause a person to eat more than they need, hence gain weight and at that time the allergy kicks in and diabetes is a result.