If they needed incentive to speed up...then they need their heads examined.
Anyone with even the slightest grasp of the situation knew that even a decent/solid Star Wars movie was going to get a ridiculous reaction...
Why?...well we know why...
But anyway...unlike avatar, the "delay" here was to use the new material. I see why they did it now...because it's basically just a modern reboot so use what it fresh...I guess.
I'll never agree with that approach. They could have given the classic movies more sustained life by building an area themed around those...and expansion, really...had that roll out say 2016...and then did the fresh material for a 2020 ish opening or later to keep the train rolling.
There are tons of reason they didn't...primary being we'll spend for the current load of nothing...so why spend if the kids don't know they're eating S.O.S.?
So additions are "strategic".
If there had been a real backlash for the last few years of increased costs and lower investment...the stormtroopers would be pouring concrete and painting to open Star Wars land next week.
Such is life.