No, I don't think it would be.
As for where they would even put another airport in the NYC area, well, they tried this out in Morris County NJ
(30 miles from NYC) back in the 1970s, but the area they were thinking of was turned into a protected wildlife zone (Great Swamp Wildlife Preserve).
If anything, I could see SWF
(about 50 miles North or NYC) perhaps getting a bit busier, but only with domestic flights to serve the growing lower and mid Hudson Valley area of the region.
for Eastern Canada flights) pretty much have things covered internationally and will for decades to come, especially if they ever figure out how to reconfigure the airspace over NYC (something I keep hearing about every few months, but nothing ever seems to get done about it).