I don't think it was "very considered" until the FA Cup final. It seriously seems like a streak of 3 good but also very lucky games turned the corner for Ten Hag, but I am convinced he was destined to leave before the final game, and that would be the right decision to make as it was after a full season of miserable results, breaking all sorts of negative records and playing as terrible football as this club has seen.
I can understand that it's all about trophies, but people seem to think "the review" is just checking if Ten Hag achieved all the KPIs. Is he staying because he delivered a trophy (if that's the case, why did it take so long to announce?), or is he staying because all the alternative moves collapsed? I don't know, but I have my suspicions.
For this reason I am surprised he's staying. Players will see how weak his position is in the club now.