Smart delivery

Smart Delivery would be specific to the console. In order to buy a game on the PC and also be able to use it on the console, it would have to be a
Play Anywhere title.

No worries! I’m happy to help if you have any further questions ^_^

Thanks so much for answering my question so quickly and thoroughly, @RainingRoses!

Smart Delivery is for games that are being released as a Series S/X version, so you don't have to buy it a second time to upgrade. As far as I know, none of those games are being re-released with a Series S/X version so they won't have Smart Delivery.
Those games will work through backwards compatibility though.

Hello,

Yes, Xbox one games that support Smart Delivery will just have to be purchased once. If you purchase the Xbox one version of a game, you’ll receive the Series X|S version (and vice versa) when you upgrade.

Smart Delivery for Xbox Series X|S FAQ

https://news.xbox.com/en-us/2020/06/15/what-is-smart-delivery-xbox-series-x/

Another good page explaining Smart Delivery, along with the current list of games that support it:

https://www.techradar.com/uk/news/xbox-smart-delivery-explained

Smart Delivery applies to both digital games and physical disks and your game progress will carry over, as normal, when you upgrade your console.

You also don’t need to do anything in terms of choosing a version to download, the system will automatically take care of that for you.

I hope this information helps, happy gaming!