You might be correct. Maybe Spiderman can take it up depending on how they go with him. I think you have some X-Men that could do it as well. In my mind, if they want to get to this level again, it's another 10 year build at least.
Though what I think may hurt as much as anything is they are kind of out of characters that non-comic people would know. I grew up on cartoons where I would know the current characters (at least a lot of them) Saturday mornings. The next generation getting introduced are almost all groups/characters that I know absolutely nothing about, and it does have me a bit less interested in them (a bit, trailers will win me over). It was mentioned in the Aladdin thread, but applies here as well: Nostalgia works. That said, Dr. Strange is legit one of my favorite Avengers now, and I knew nothing of him before the movie (that I thought I would hate and really liked), so they can win people over when done right, but my point is I think the hill is a bit bigger for this next build.