I don't think any country will go back into serious lockdown again. It's probably impossible now, other than in totalitarian countries. Other than the countries who (so far) got almost completely on top of the virus from the start (due to geographic remoteness or past experience with these kind of virus), everywhere else is probably now implementing (or well on the way to implementing) the Swedish model, although no government would openly admit that.
After the pandemic is over, history will provide the data to help us decide whether adopting the Swedish model from the start (as opposed to morphing into it after an initial lockdown) might have led to a better overall outcome (i.e., a similar health outcome but a better economic outcome). The judgement is important, because future pandemics seem likely.