This was the excuse, but it doesn't hold water. The admin were actively trying to get people to endorse the CR. Arguably, the shut down would have been enough of a limit point and potential catastrophe that they would not have been able to actually use it to effect a "takeover"—instead it might've been the necessary fuel to effect a turning point toward restricting some of these efforts—they know they cannot gut everything, the goal is to keep a skeleton in place so that they can keep up the appearance of "improvement" while they dismantle, a full shut down would have made that parlor trick ineffective.

I don't know if Schumer had other motivations or if he just made the biggest blunder of his political career, either way it has not turned out well for him—not only are people actively calling for him to be replaced, it's clear that history will not remember this supposedly necessary shut down prevention as something "heroic".