Tptb would be stupid to skip the Occlumency lesson scenes though I wonder if they will show us Snape's Worst Memory only because they've not bothered to go into any detail on the Maurauders and Snape's rivalry with them before (aka The Shrieking Shack in PoA.) Criminal, yes but they've been known to skip things that us fans feel are so crucial to the storyline because it's not directly relevant to The Boy Who Lived. If JKR is smart, she will tell David Yates he needs to start introducing more of Snape's background since HBP is the turning point, when Snape begins to become more front and center to the crux of the matter.