As mentioned, SQ 1/2 is changing to a 77W from 744.

That means, as far as I can see, that the only flights from / to the US on SQ with premium awards will be SQ11/12 LAX-HKG-SIN and SQ25/26 JFK-FRA-SIN. From North America, possibly SQ17/18 YVR-SIN as well

They only have a dozen or so 744's left compared to 777 and A380 aircraft so one wonders how long it will be before we're completely shut out of premium and/or whether they'll eventually allow premium awards in their 'ginormous' new C and F seats.