There are a lot of unknowns so I doubt anyone really knows -- probably including people within SQ -- but I wouldn't be optimistic. Singapore and a lot of other Asian countries (and Australia) appear to be in no hurry to reopen borders, limiting demand for longhaul travel to and from Asia. Plus there's the complication that the SQ A380 fleet is planned to shrink and this route takes up a lot of A380 fleet time, so they may no longer find it the best use of that aircraft. If I had to bet, I'd guess that JFK-SIN nonstop is the only SQ service to NYC going forward, but I'd be thrilled to be proven wrong.
(On the other hand, who knows, but I guess if US-Europe reopens, SQ might restart this route just to make some money carrying relatively unrestricted traffic on JFK-FRA while most of its markets closer to home are severely limited.)