I believe that the fear of the GT starting any day, any minute, any second is much more powerful and long lasting than actually claiming or hinting that it started.
Once they claim the GT has started, no matter how long they stretch it out, it will lose some of its boogey man scariness to the rank and file. I know they live in anticipation of it but deep down I think many dubs fear it as well, especially the ones that believe but know they've been baaaaaaad.
By not starting it but scaring the crap out of everyone that the GT boogey man is coming any second by showing bunker videos and talking up possible persecution scenarios they can keep the sheeple in line and donating - just hoping and praying and paying that the GT starts soon to end their misery. But, fearful of what actually happens once it does start.