The main reason because Hiir Noivl is confused is the same as mine, they did specify on the PS3 example that you need to register the 2 copy to 2 different Service Account (inside the same SE Account), which means you will have to pay for 2 subscriptions.

But, they forget to also tell it in the Windows+Windows example, which lead people to think that you can register your 2 copy of the game inside the same Service Account, and then only pay for one subscription.

The confusing thing is why writing it in PS3 example and not in the Windows example, because obviously both will need copy to be registered to 2 different Service Account, and there will be 2 subscriptions.

So, as Hiir Noivl, I think they should modify a bit that support page, it's a bit confused, even if I know how this work, other people can make mistakes easily.