Once testing becomes widespread enough that it's feasible to test a lot more people it's quite plausible to relax the restrictions. One big problem before the recent "shelter in place" state is that community transmission by asymptomatic people was/is out of control.
If only strongly symptomatic people are "allowed" to be tested and health care professions aren't tested, it's basically impossible to restrict spread of something as infectious as covid-19. And once people with a lot of contacts have it, and stay in contact, further spread will obviously accelerate.
If you look at the buildup of test capacity in the US (far far to late obviously), it's improving at a decent rate (from a totally embarrassing starting point):
https://covidtracking.com/us-daily/
(there's a lot of differening sources, several lagging, but the trend is similar afaictl)
So there finally does appear to be some serious and successful effort in building up test capacity. Testing everyone in the US seems far off still though.
Given the rates of hospitalization and available beds / respirators, it'd however be insane to rely on testing at this point. Spread would be far too fast, and there's obviously not enough testing.
But if infections slow down due to the isolation, and testing ramps up at the same time...