I think these fires are a rare event so there is time to think this through carefully,millions has been raised for them and it needs to be put to longer term accomodation for them,it's unlikely although not impossible there will be a similar event in the short term,having said that if i was up high in one of those blocks i would want out asap
The risk of a similar event must have increased significantly after Grenfell. There will have been people, either terrorists or arsonists, who will have watched the Grenfell fire and have set their sights on a repeat.
An overnight evacuation does seem a touch OTT. Perhaps emergency measures such as a 24/7 fire warden service might have been sufficient for a week or so. But Grenfell isn't like natural disasters, which might be classed as "a one in a hundred years event". It happened because of dangerous building practices which could be widespread. And sadly we live in a world where people will look to exploit that.