My understanding is Microsoft where planning to let devs target all 4 models and would do so for a while (I seem to remember Microsoft planned to target all 4 for their own releases for a while). I guess its the advantage of using AMD APUs. You just tweak the resolution, textures etc to work with what you want. I suspect some will only work on the newer generation though. Microsoft's plan is now nothing to do with hardware. It's all about game pass. If they can get you playing on a old Xbox one they will - Its more subscriptions. Add in support for streaming games and bang you can game on anything and Microsoft still sell Game Pass. Its like everything these days - subscriptions are king.