Since Dynasty 8 was going to be a site where you could buy houses and this feature was taken out of the game, Rockstar made the 8 riddle thingy that all have to do with Dynasty 8? Ok, this is probably just my mind working weirdly.
I've seen some people saying this at the old topic and EVERYONE were just ignoring it:
What IF the jetpack were a prize for completing 100% of the game. I mean, the true 100%, not the fake one. Completing everything considering whats left at Social Club. Like the rest of the knife flights, under bridges and so on.
Fake 100% = UFO at the top of Mt Chilliad and Big Foot mission
True 100% = Jetpack being dropped from the same UFO, or at the elevator in fort zancudo...
Probably there is some prize beyond the fake 100%. If there isn't, why there would be 50 flights under bridges?