Mine is already done with 1st install - Single Dwelling Unit Residential OH Feed alternate L2C solution required on 2nd January.
The exterior part is done, not the internal part.
I had both parts done when I got FTTP 2 weeks odd before my activation date as the guys had time to do both parts by chance as it was supposed to be a more complex job to get the fibre to the house than it actually was.
Even though ONT and everything was in place I still had to wait for the activation date regardless and on the day it just went live after the same OR guy phoned me to double check it switched on.
It sounds like they have had engineer shortages/delays that is preventing your internal half being done thus rescheduled.