1. I was part of the first phase on the development Feb 2017, all are sold(100), they are now on phase 2.
A few years ago when Openreach first started offering FTTP at no additional cost to developers, the threshold was a minimum of 100 homes. This threshold was lowered to 30 homes in from Nov 2016 so it may have been your developer had already requested copper from Openreach
before Nov 2016. I'm sure you know well that developers will always take the cheapest option and copper was cheaper than FTTP at the time from Openreach
TBH I would just be grateful that you've at least got FTTC, there's many horror stories of new build buyers stuck with a sub 3 Mbps ADSL service even in recent times.