This is a very common way to count deaths actually. For example, when people die of AIDs, they aren’t actually dying of AIDs. The complications from AIDs is what leads to it.

For example, Smoking kills hundreds of thousands people every year. It’s not cigarette smoke that’s killing them directly but it leads to the lung cancer, the throat cancer, exacerbates whatever underlying condition that person has.

For COVID most countries are doing it the way you are describing. It’s a fact that how Sweden is handling the virus will lead to more human contact and more disease spread. That just leads to more deaths, there’s no way around that. You are correct that it’s yet to be seen what strategy is working and what isn’t because the dust hasn’t settled yet.