Having been involved in new hotel projects for a number of years previously you would be surprised at how unfinished things seem up until the last minute - I used to be quite alarmed at points but it (almost) always came together
It does look pretty far from being operational though - considering the challenges BA had opening T5 in a pretty "big bang" style if you are travelling in the first few weeks I would expect some chaos personally. Flying through on 21st Dec so hopefully things are rather sorted by then
I hope the electronic restrictions are lifted with the move!