I was thinking this last night - if DBGT 2016 version was so going to be so technologically advanced, groundbreaking etc. etc. they shouldn't have tried to rush it through and put unrealistic opening dates out there just for the sake of having it open. Merlin seem to have a habit of putting exact dates out there instead of just being vague with "Coming soon" - Smiler being a case in point, they announced at the start of the year an exact opening date, and anyone could see from construction it wouldn't be ready in time.
I know the tech of DBGTROTD means the ride can evolve, change etc. over time but I'm sure they weren't expecting or anticipating having to add to the ride so dramatically after one (half-ish) of a season?