The announcement on the TTP website has been updated:
Out of an abundance of caution and in the interest of minimizing exposure and controlling the spread of the Novel Coronavirus Disease (COVID-19) Outbreak, all US Customs and Border Protection (CBP) Trusted Traveler Program Enrollment Centers will suspend operations until at least August 10, 2020. This temporary closure includes all public access to Global Entry, NEXUS, SENTRI, and FAST enrollment locations. We sincerely apologize for the inconvenience and appreciate your patience through this process. Enrollment on Arrival remains operational at participating airports.