I don't see a better season than this for Tottenham. They winning Europa League, and qualify for the UCL, though they had terrible performance and finished at 17th. However, we know so well how Europa League is a major trophy, and not many teams owned it.
It would better if they gave Ange another chance, but their owner is just an impatient person, and sacked him after a dramatic won in the final of Europa League. I'm surely they will get a factory reset next season. Play badly, no achievement, and finish at the bottom table.
If you look at it from a Premier League perspective it's clear that Ange Postcoglou has not made any major changes and I agree with that when he was sacked, but winning the Europa League is a great achievement because Tottenham haven't won anything for a long time. Tottenham are looking to achieve better results in the Premier League and that may be why Ange Postcoglou was sacked.
The success that Ange Postcoglou has given him should have been enough strength for him to stay at Tottenham so that he can still be given the chance to be a coach next season. If they want to do an evaluation then what needs to be done is to bring in a number of players that are needed so that Tottenham can be much stronger, not the opposite, firing Ange Postcoglou.