There are 2 birds in QPG at the moment suggesting the refits are beginning in earnest through the quieter winter season. It will be interesting to see how many days it takes for the first one to come out. The first 77W took 80 days for a dream cabin refit with most others taking about 40 days.
I have a an A330 flight to Madrid in mid-June that still shows the original 1-1-1 J cabin - it’ll be interesting to see how many are done by then (especially if they are doing 2 at a time).