Health,
If your goal is to advocate for the frum population to make a healthier lifestyle (e.g., healthier eating habits and increased exercise), it would be good salesmanship to avoid anything that may sound like a knock against frum culture.
Also, I think the ads you mention skew more towards younger people because their deaths R”L are usually unexpected, and therefore there is a higher chance that there wasn’t a completed plan of support for their dependents. I don’t think we can derive statistics from those ads. Also, the causes of death cited in those ads tend to be things like cancer or accidents, not obesity related disease.