I believe Singapore now has 6 planes with the new config.
9V-SKQ was quietly rolled out Jan 9 and has flown to HKG, FRA-JFK, SYD (the frequency not regularly served by the new A380s) and BJS. I don't have first hand confirmation, but why would a plane sit in the hangar for 4.5 months and not be retrofitted? I'm betting another retroffited one (9V-SKS) would come out end of March. 9V-SKF went into the hangar about a week ago. At 4.5 months per retrofit, this will keep to Singapore's intended completion date of end of 2020.
RoutesOnline is saying Singapore filed for a change in A380 passenger aircraft capacity effective 01 June (379-seater to 441-seater) for the SIN-FRA-JFK route. Singapore should have at least 8 retrofitted aircraft by June if my calculations are correct. That should increase retrofitted reliability shouldn't it?