It already upconverts PS2 and PS1 games. Remember that upconverting isn't the same as rendering at higher resolutions.
Upconverting simply takes a lower resolution render, and scales each frame up to whatever your TV display can take.
Meanwhile, the requested feature of rendering the game at higher resolutions hasn't been implemented, and no one knows if it will be.
With Ps1 and PS2 games it's actually a bit more difficult to rerender things at higher resolution because so many different developers and games used different methods to render. There was no, or a low end, graphics chip in the PS2 so graphics calls didn't all go through one chip to write a wrapper for.
However, we know it can be done because the PS2 devkits had a way where you could render at much higher resolutions, this was usually used for stills and movies for ads.
