I can’t say that your predictions are wrong yet, but your order is definitely wrong.
C#/Mono support officially from Epic is the unlikeliest thing to happen, ever. There is 0 need for C# in UE4. You have BP for those who don’t like code, and C++ for those who like code. Anything in between in unnecessary and maintaining that would distract Epic from more important stuff.
Destruction 2.0 does not have a chance of Medium, but 0. Epic is not currently working on destruction, it’s backlogged.
They can show Niagara, the code is in master and everyone can take a look and use it already. So nothing would stop them from talking about it.