Something can't be delayed without a release date.
Rita saying "hopefully it'll come out by Monday" isn't a release date.
Her sister had said March with the Rimmel campaign since January.
Also, I'm pretty sure they had a premiere date this week, because why would Rita say something like that without knowing around when it's coming? They obviously had something planned for this week.
But March 8th does not work as a release date, I think they would put it up for a pre-order first if they're releasing it in UK first, but if they would release in US first, it wouldn't make sense as well, since it's Saturday, and they release stuff mostly on Tuesdays... I'm confused.