I'm not sure about the 'Smoke Monster' being behind the "resurrection" of people. When the smoke monster comes out of its holes, Ben's torch goes out. When it goes back into its holes, his torch relights. However when Alex shows up, nothing. His torch stays on, so I'm gonna say no, the 'Monster' is not what the people are. I also do not think the "people" on the plane are Widmores people. I think they are possibly Dharma people. If they were Widmores people, why would they not take out Ben when Ben says his name is Benjamin Linus?