I don't believe Riri and Doom was editorial interference, because its clear that they were both Bendis' ideas. Most I could say is maybe time got crunched because editorial wanted the books to start by a certain time so Invincible and International had to end earlier than he wanted.
However, like Confuzzled mentioned, Bendis is notorious for throwing too much into a story at once never giving time for any of it to be developed. The Search For Tony Stark is the perfect example of a story with too much going on, and yet nothing happening at all.
So it feels to me like it was a case of he jumped on putting MJ into his book right away, but then he started adding more and more on top of it, so MJ didn't get to have much attention as everything else fought for screen time.