Basically they're saying that they decide to exclude Bran because he's caught up to his ADWD material, and they feel like adapting his TWOW material onscreen in season 5 would make him too ahead of other characters' which wouldn't sync well. They also think that showing Bran's training onscreen would be "not cinematic".
Which is all BS because:
-Sansa is also caught up to her AFFC material, but she's gonna be in the next season.
-They've given Yara/Asha a scene in Seasons 3-4 even though she had no book material in ASOS.
-They gave Theon/Ramsay scenes in Season 3-4 when they weren't in ASOS.
The fact that they're cutting out a STARK for the entire season is just ridiculous.