PSAS definitely had some design and roster issues but it was doomed to fail because Sony had no faith in the project to begin with. They pulled the plug the first chance they got and completely screwed over Superbot.
As much potential as a sequel could have, I don't see modern day Sony being all that interested either, nor do I think they'd handle it any better than the original tbh.
To get a sequel, an established dev/studio that Sony is actually willing to give the time of day to would probably need to propose and spearhead the project.