The change in the audience demo is more or less expected. It's the hardcore fan audience that is most front-loaded.
That's one reason why Wonder Woman had such an unusually high domestic multiplier for a superhero movie. It wasn't that highly anticipated by fans, due to bad buzz surrounding the DCEU at that time, so it ended up performing almost like an animated film, or a family movie.
This movie will be more front-loaded, due to the hype surrounding the MCU, but it will probably pick up more of the family and casual moviegoer audience over time and have a solid multiplier.