Pirates etc... Part of the patch cadence problem is that the "story" ends long before the new expansion. Epilogues don't make good drama. Their solution would probably be a filler event involving some kind of random out of the blue surprise "attack".
They skimmed over the new holiday event pretty quickly but it seems like it should be fairly obvious that its mardi gras based on the items mined.
add more raids cut the seasons...... 6 months is too long for 1 raid tier with only 9 bosses and the same dungeons. make them 4 moths or even 3