Existing Xbox One Games with Gold titles will move over for Game Pass Core subscribers - as long as they've been redeemed on the same account. So, any Games with Gold games that you've redeemed since the program began will still be accessible if you subscribe to Xbox Game Pass Core, or Game Pass Ultimate.
Of course, when it comes to Xbox 360 titles, they've always been permanently tied to our Xbox accounts anyway, without the need to remain subscribed to Gold. This will continue to be the case when Game Pass Core goes live - all redeemed Xbox 360 Games with Gold titles will still be accessible, without any subscription required.
Although this big switch will mark the end of the GWG program, Microsoft will be introducing a new perk for Game Pass Core members. From September when the new Game Pass tier goes live, Xbox Game Pass Core will be getting its own library of titles, to be expanded "2-3 times a year".
Microsoft has revealed 19 of the 25 games that will make up this collection at launch, which you can view down below. The remaining six titles will be unveiled in the run up to launch - Xbox Game Pass Core goes live September 14th.