Are alternations between shelter in place and free roam going to be a pattern

Anyone know if this idea is true? I heard that one plan is to have people shelter in place for a month or two, then have them roam freely (or at least the low risk people roam freely, ie anyone under age 60 without serious comorbid conditions).

Over time it’ll build herd immunity and protect the highest risk.

Is this a legitimate tactic for dealing with the virus?