From VG247: “The Division 2s very own Public Test Server (PTS) will be available ahead of the games third major update.
During this weeks State of the Game livestream, The Division 2 developer Massive confirmed that the PTS will return in The Division 2. The games next big update, simply called Title Update 3, will be the subject of the first test.”
Source: N4G PC The Division 2 is getting a test server