MCU movies like to payoff long term by homage to plots and moments from previous films

Crazy theory time: Doomsday is mixing parts of the plot from both Iron Man and The Avengers. It goes in line with RDJ being Doom and these two films being a “beginning story”

I think the final battle will be intercut Nolan style between Latveria and New York. Some of the unannounced characters will be in New York fighting and we’ll get them in Secret Wars