I disagree greatly. I did the BFA pre-patch event on two characters and it was a short questline that was dragged out by time gating.
Legions pre-patch event had me playing ALL of my characters; even the ones I haven't played in years! The epic feeling you got when flying from boss-to-boss in all the zones assaulted by the Legion. That's hard to top. Not to mention the extremely fun WotLK event!