It's now official, Tottenham has fired Postecoglou today according to Popular football transfer journalist, Fabrizio. The very day that Tottenham won that trophy against Manchester United, I was seeing how Tottenham broke a 17 years old trophy drought I went online to make little research and I saw how Tottenham had sacked the coaches that once won a major trophy for the club after the club went without trophies for some years. Then I knew that sooner or later Tottenham was still gonna repeat it's history of sacking the coach that won them something. Today, it's been confirmed by Fabrizio

Tottenham Hotspur are known for sacking their coaches either towards final of a competition or after the finals irrespective of performance. It didn't surprise me that Postecoglou has been shown the exit door despite winning for them the Europa trophy after all these years of going trophyless. They did same to Jose Mourinho when he was manager there, after taking them to the finals, just few days to the game he was sacked. Lol.
Tottenham Hotspur have not learned from their mistakes and continue to make the same mistakes, it is disappointing that Tottenham Hotspur have been so quick to sack someone who has achieved all their goals, played in the Champions League this season and won trophies in a team that has been plagued by injuries. Tottenham Hotspur are notorious for sacking managers as you say, but sacking a manager who has given them the trophies they have been waiting for is a big mistake.
Tottenham Hotspur are in a period where they are looking to bounce back for next season after winning trophies this season. The risk that Tottenham Hotspur are taking is huge with a new manager coming in as they will have to rebuild the squad to their liking, the pressure on the next manager will now be much greater, because the manager Postecoglou who gave them the trophies was sacked, let alone the new manager who will be sacked again if he doesn't get anything at the end of the season. For me it is unethical to sack a manager when he has given the team trophies and new hope.