Some activation dates have been delayed for almost a year. Many people could have upgraded their connections for another year with that time frame. Not as fast as FTTC maybe, but faster all the same.
Maybe BT wanted to keep them dangling to prevent that from happening?
It did sound all a bit too optimistic with their "speeding up their roll out" statements over the last year.
Knowing how it works is completely different to understanding how it works.