Honestly I won't expect much knowing SQ.
The meals will be possibly similar to their current nonstop between SIN and SFO. Basically a full meal after takeoff, a meal in the middle of the flight, and then some kind of snacks throughout the flight.
Pajamas - not going to happen
Amenity kit - they don't have amenity kit in business class to begin with, so I don't expect SQ to be reintroducing them.
Just don't expect anything extra and you will be a happy passenger.
Carfield