One problem here is that you know about the outcome. If the outcome is going to be public, this creates a different type of competing pressure, where classmates are invited to compete with each other, while the one they should be competing with, is themselves.

It is like you have a teacher saying: 'my previous year's group, they were like so amazing [exhibit 1, 2, 3, ...]' and you know your group is never going to reach those limits -> #very_demotivational since in many ways, the way people are isn't going to be malleable. So a teacher is going to have to work with the material they got, and take that as a starting point. So instead, the teacher needs to have the intelligence acting like an adult, and refraining from expressing said enthusiasm.

I believe, if the results are discussed 1[-3] on 1 ie. in private chat, there is more room for openness, honesty, humbleness, and -yes- humility. On a macro level, this also exists on schools. Like, when the parents come to school to discuss their child's performance, it is a private setting without the other children and other parents, but with teacher, child, and parents. 1[-3] is still a private setting, but there are still things the child would only discuss with their parents, or only with their teacher. You could also achieve this in small groups on school, but as soon as you got a too big group there's this huge competing factor going out. Which is going to trample individuals. The shy kid isn't going to have their say, the ADHD kid gets annoying, ... and it can be tackled, with smaller classes.