Dr. Doom being the new big bad makes sense, he's a great villain. But casting RDJ is colossal fuck-up. He costs one hundred million dollars and just screams of nostalgia bait/desperation. You're already turning off a good portion of fans who are cynical about the casting. Why not use someone like Mads Mikkelsen (or a Skarsgaard) who's gonna be undoubtedly cheaper?

They also fucked up with the whole multiverse bullshit. We have
>X-Men coming from the post-credits scene of the Marvels, which nobody saw
>Fantastic Four from a completely different universe
>TWO teams of Avengers from the original universe, where both their movies bombed (Captain America Black New World and Thunderbolts)

And from what I can see, Avengers Doomsday is gonna have a goofy tone. The Thunderbolts post credits scene is directed by the Russos and it's quips quips quips. It's a fucking disaster.