Yeah they could have just delayed for another 1 week and open on 4th Jan Monday if they really wanted to to do that (avoiding the festive holidays).
My guess is that they really wanted phase 3 to be inked down as "happened in year 2020".
Coz as we can see from the new phase 3 measures, basically they are just a small increase of the present limits of pax.
Those waiting for SMs to be done away with,
mainly the mask wearing thingy 
, can continue to wait long long.