I don't think Feige and Marvel Studios is a very relevant comparison overall, because the whole thing was such an underdog and upstart venture to begin with.
It could have failed, and then the whole thing would have gone under. But, by the time Age of Ultron rolled around, the MCU experiment had already succeeded so far beyond anyone's original expectations that a somewhat under-whelming Avengers sequel hardly mattered.
The MCU started with nothing and built itself into one of the most successful franchises worldwide.
Star Wars is not an upstart or an underdog. It is probably the biggest pop culture franchise in North America. Internationally, it is more of a mixed bag, though Star Wars certainly does very well in a lot of places.
So this franchise needs to be evaluated with that in mind. There is a whole spectrum of possible reactions in between "Fire everyone!" and "Everything is great!"
I think this movie won't justify either of those reactions. At the box office, it is probably going to be perceived as a little disappointing, but not overly so, depending on where the movie ends up, exactly.
But there are other factors to consider, such as the long-term strategy. So, we'll see. It's an interesting case.
