The release date is still a while away. More theaters should be adding them to their listings and making tickets available for purchase as we get closer to April.
Perhaps this season 3 theater showing will be much more limited compared to the first two seasons?
I doubt these showings are really for the fans, their main purpose is just advertising for the TNG Blu-Ray releases. I don't see CBS being able to get to showing a couple of episodes from each season of TNG, sadly. We have been pretty lucky to get as much as we have so far.
But I really hope they will eventually show "All Good Things" as a feature length movie!