Heidi Klum and Tim Gunn are also exiting the unscripted series to topline a new fashion reality series for Amazon Prime Video.
“Threads: Paintings from the 1960s and ’70s” will run though June 23 before Schnabel launches another exhibition of Posen’s work in Switzerland.
“Right now, I’m staying away from bringing my brand into politics," Posen said.
The full-service building was designed by architect Emery Roth and constructed in 1928.
Dasha Zhukova, Priyanka Chopra, Christie Brinkley and Georgina Chapman are among the moms hosting the event.
Delta Air Lines has rejected a series of Posen’s early designs because they are too fabulous, fussy and fitted.