Speculation that Schumer is afraid of Osacio-Cortez primarying him
Redistricting might mean Osacio-Cortez will lose her seat, in which case she could run for Schumer's senate seat. Speculation that Schumer's vote against USMCA was to protect himself in that event. But he also voted against NAFTA.
With Osacio-Cortez's star power I'd be suprised if her seat disappears. On the other hand, I think the state government dislikes her because of the Amazon thing. And other congressional democrats nearby also seem to not like her. So maybe politics can't defy gravity forever.