Ms. Marvel book does not sell very good. Diamond (the selling for retailers in the US) puts the book in the 30000 copies area with a steady slow decline.
the books of 20000 and below are those which usually get canceled.
The reason for the titular character change is definitely about boosting sales during Dark Reign. But this does not mean the slaughtering of Carol, just a temporary change in direction, like all Dark Reign titles.
Now, Hermiod - just think about it. If the reason for not putting a funeral issue is "People do not care enough", do you really think they would publish one-shots like "Ms. Marvel - Storyteller"? A funeral one-shot would sell better for sure. Esp. if you can put "Dark Reign" tag on the cover.
Also, people care more about Wasp in "Mighty Avengers" than about Carol Danvers in "Ms. Marvel"? She really isn't some random character.
Carol Danvers just joined the New Avengers. She appeared in 48 and 49 and on the cover of 50. Bendis announced in an interview, the same day Brian Reed tried to market the death of Carol Danvers, that Carol will be a big part in New Avengers.
As for the Simon thing, I read somewhere that Bendis mentioning Wonder Man to appear in New Avengers 51. Also, I clearly remember Reed answering in his board to Wonder Man fan, that Wonder Man will appear in the Avengers and will continue a plot started in Ms. Marvel (The only plot he got there was romance with Carol).