Well California has been smashing expectations for tests performed, but it doesn't seem to be doing anything to help stem the rise in cases. I don't think there is enough contact tracing that follows the testing...
The only chance of that, is if the demographics of those testing positive now are different than those testing positive 1 to 3 months ago. Or if the virus has mutated yet again beyond the European strain that initially infected the eastern seaboard in Januaryish.
It could also be spreading too fast or be too widespread for contact tracing to contain. Most states also don’t have enough people doing contact tracing. California has about 6k, but needs at least double that for contact tracing to be effective. https://www.kpbs.org/news/2020/jul/07/how-contact-tracing-going-san-diego/
It's a fact that demographics are different, and also a fact that average hospital stays are shorter. The question is whether those facts will last, or if we will see spread back into the vulnerable populations.