Ok, this is interesting. Some of this fits my intuitions, and some was a surprise to me, so yes, this does modify my view, but only slightly.
It seems there are preventative measures that are cost effective, and there are others that are not. So really, this indicates a need to determine a threshold. Perhaps we determine that we can afford to pay up to $50,000 per QALY, and cover any care that falls within that limit. So, we'd have coverage based on its efficiency rather than whether it is considered preventative or treatment or maintenance. The idea being to get the maximum amount of healthy years of life out of whatever amount of money we as society are willing to put toward healthcare. This could also be extended to programs outside of direct care, like some of those articles suggest, which encourage and support healthy activity in a way that still falls within the $/QALY target.
Of course, I expect it would be a bear to fairly study every possible treatment and program to determine its efficiency, especially factoring in a changing environment which is bound to change the efficiency of any given treatment from year to year.
Still, at a minimum, we should be grabbing those low-hanging fruits, where we can gain healthy years for a very low cost.