Eventhough it's a good thing that the Semis and the finals are postponed because of COVID-19 outbreak, it really sucks from a cricketing fan perspective that we have to wait nearly a month to watch the semis and the final.
Just for record "One Month" is not coming from any official source or any sort of source. It was me, just speculating the timeline, so plz don't take my words for granted. If that's the case.
But playing after 1 month will also be not fair because all the current momentum of the teams and players will be lost. At that moment anyone can win the match and the present form of the teams and players will not matter.
Its part of the package and its for all 4 teams.
About giving trophy to top team; There might be some logic on your argument but unfortunately that's not how works in competitive tournaments. They can't hand over the trophy to top ranking team when more than 3 teams are in the final stage.