You can do it before shipping the game and better yet it's guaranteed to work everywhere at nearly no performance hit. If storage space is a concern then you can use texture compression as well ...
And texture streaming is an orthogonal issue altogether. Inferencing shaders can't really beat texture sampling hardware when it comes to these tasks and they have optimized compression paths too ...
I/O traffic stopped being a bottleneck ironically since the new consoles introduced SSDs so using ML to minimize this traffic isn't going to matter in the slightest. A better case for ML texture upscaling would've been on systems using an HDDs since high I/O traffic would prove to be a bottleneck ...
If you do it before shipping the game you lose all the advantages. Basically losing everything the MS Game Stack manager was talking about.
And clearly it's not an orthogonal issue if up-resing from memory can have a very direct impact on streamed data. I mean that literally goes against the actual definition of what orthogonal means!
MS Game Stack offers a multiplatform set of tools (some for Playstation too), so it probably could help HDDs too in some capacity, when they're ready to offer it.
So why having an ultra fast SSD ? [emoji6]
Well, there's an awful lot more than textures you may want to stream, and you'll still be streaming lots of texture data even if you wanted to up-res say you final, highest res mip-level. And if there was no benefit to saying on transfers from, say the XSX SSD, why would Sony have shot for something more than twice as fast?
I see ML for textures something more useful in Stadia-like consoles.
Trouble there is you've already gone past the texture sampling stage, and are at the point of a final image. But you do raise a very interesting point that have a DLSS like step in a Stadia like mini console could be a really cool step to improve the service.
For example, a 2060 is a fairly large chip but if you were to strip out everything but the tensor cores required to DLSS a good base image up to a very high quality 1080p, and you'd have a better output than current Stadia, with probably lower rendering requirements, lower power requirements, and lower latency and transmission BW than they currently do for the low quality stuff they currently send out.
Maybe the future of streaming boxes is a basically a little tensor box ....