There is part of one sentence in there that I think people shouldn't lose sight of. "...if that trend is correct..." It may be educated speculation but its still only speculation.
The number and percentages have been done to death in the last 2.5 years, along with those at GE's. There's a trend there that is worth noting too. When its close, it can't be predicted with any certainty.
I’m sure it would’ve been dismissed if it had shown those new voters favouring leave