1. High-fat diets, as done in your 3rd paper and as done in most "high fat" studies, are incorrectly labeled such. "High-fat diet (HFD, n = 10: 55 % fat/25 % saturated fat/27 % carbohydrate)"[0] is not what the parent meant by "reducing sugar and carbs altogether instead of promoting whole grains as they do." A more honest interpretation would be "max 40g carbs, the rest fats and proteins." This is because the main benefits of such a diet only come out when carbohydrates are severely restricted -- as has been known for a while now.
2. Linking papers, without any sort of commentary or notion as to the reason for their inclusion, is in poor taste. In most cases this is done when the poster themselves haven't thoroughly read the articles in question. I won't go so far as to say this has been done today, but I will say it is a disrespect of our time to post lengthy papers without any sort of reasoning behind why they've been posted.
3. The first two links (technically one paper)[1][2] are statistical analyses of different food groups and their association with type 2 diabetes. The same error is done here as has been mentioned in my first point: without controlling for the whole diet, and using a very low carb, high fat/protein diet, the findings are irrelevant. Risk ratios are a notable finding, not a be-all end-all. Correlation is not causation. Continue platitudes ad infinitum and ad nauseam.
[0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5291812/ [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5506108/ [2] https://onlinelibrary.wiley.com/doi/full/10.1002/ijc.31198