Never happen. That would put people out of the theater at 10 pm, local time. Plus, as much as I love BoBW and Trek, sitting through a 90-ish minute double episode was hard at the end. I'd prefer to have Emissary on its own...but I hold out no hope of DS9 getting a theater release.
For this to happen, the start time would need to be earlier in the evening and that would be very difficult for some people coming from work.