Age Adjusted means it follows an age distribution like this:

https://www.indexmundi.com/graphs/population-pyramids/united-states-population-pyramid-2020.jpg

So, they adjust the average death per state adjusted by age.

The only reason you'd do it this way is to obscure the likely demographic for death.

In other words, they are likely adjusting by age solely to hide data which indicates under-60s have almost no threat of death.