So...... where is this big premium for this long and skinny route that I've been reading about, exactly?
What you're seeing is the efficiency of the A359 at work. The premium for the non-stop doesn't have to be that high.
Except that airlines don't price premium fares relative to the performance of the aircraft, they price them on what the market will bear.
Excluding adjustments for competitive necessity: if they suddenly get an aircraft that can do the route at less cost, they're going to pocket the savings, not drop the premium fare.
Is this lowering of fares by SQ on a "premier route" a tacit admission by SQ that its current high premium fares are non sustainable into the future?
What you're seeing is more a consequence of the fact that ULH has expanded dramatically since the days that the SIN nonstop option first launched.
Back in 2004, the only remotely comparable flight was CO's single daily EWR-HKG. Now, NYC-HKG is 5x daily, on multiple carriers, from multiple gateways. NYC-TPE is now multiple times daily as well. Soon, NYC-MNL nonstops are going to be starting. These are all 16hr+ flights (unheard of 20yrs ago) that arrive into connecting banks that can efficiently transit you to anywhere in Asia, and almost always with a shorter geographic distance traveled than connecting at SIN.
HKG is the powerhouse gateway for connecting N.America to SE Asia, with TPE not far behind. MNL is getting in on the action; and even NRT/ICN offer more efficient (distance-wise) connections between the USA and almost anywhere in Asia, than SIN does.
It's more difficult for SQ to justify any atypically high price on that route, than it would've been previously. Even for SIN O&D:
Yes time is money, but if someone had to fly the route and SQ's single daily timing didn't work for them: then they can hop on any number of CX flights NYC-HKG, have the option of F class which SQ isn't offering on the nonstop, and still get to SIN in around the same in-air time with a brief connection and multiple timing options @HKG as well.
That's hard to fight.
Like I said, that flight often clocked at well above 19 hours.
That was then.
They now have an aircraft that cruises at 0.85M (versus 0.82M), and as AI has shown, route modeling has continued to improve significantly in even just the last few years.
Not only do they seem confident that they can shave about a half hour from the cruise time; but the flights will also likely have a much more direct approach into and out of NYC due to the 5am arrival times-- they won't have to deal with all the evening air traffic that the previous flight had to queue up into.
I myself, suspect a more prosaic motive... ~Thranduil