The situation after lockdown will not be the same as before lockdown.
Before lockdown, the virus was spreading like wildfire through bars, restaurants, social gatherings, schools, transport.
Now, the vast majority of the people who would have spread it NO LONGER HAVE THE VIRUS. This makes a huge difference.
The children going back to school should not have the virus.
There will still be pockets - people who didn't follow rules, people who were exposed due to their work. But it should be a totally different landscape.
In other countries, schools are going back, but restaurants etc not opening until the summer, all large crowd functions cancelled.
None of the scientists are talking about "herd immunity" as a policy so far as I know - instead the same techniques as used to suppress SARS MERS etc.
There will still be as much social distancing as reasonably possible until the risk is over - which could be by natural mutation or possibly vaccine, or effective early treatment - but not to the current extent, not hiding away or destroying businesses.
Until then, testing, tracking, local lockdowns if necessary - which would be better than everyone staying locked down.
Obviously no one knows for sure - but it is a good time to listen to good science and good medicine, wise words spoken by a leading SARS expert recently.