It will fly only to be voted down with customers feet. I know a lot of people who looked on the plane type for the first time during their holiday bookings. This plane is finished.
It's not something an airline can do hastily, as different aircraft (well, at least those of differing type rating) require different crews to operate. So the airline will have to grab a totally different crew to match their replacement aircraft.
Before the 737 Max got grounded (after the 2nd crash), I remember reports that some airlines allowed passengers to rebook their flights for free (to end up on a different plane). I doubt they will continue doing it once the 737 Max is allowed to fly again. Eg, Southwest is too dependent on it.