Most friendship disasters at eight are over by Thursday
A child comes home devastated: they are not my friend any more. The adult response scales to the visible distress, which is genuine and enormous, and frequently the friendship has resumed before the adult has finished worrying.
Friendship at this age is intense, categorical and fast-moving. Falling out and reconciling are ordinary operations, practised often, and children are considerably better at them than the adults watching.
What helps
Taking the feeling seriously without taking the verdict seriously. The upset is real; the permanence is not, and saying so gently is more useful than either dismissing it or organising a response.
What to watch for instead
A pattern that persists for weeks, exclusion that involves several children at once, or a child who stops wanting to go in at all. Those are different in kind, not in degree, and they do warrant talking to the school.