"We rocked this bitch until the wheels fell off," wrote Lala Kent, summing up the collective bittersweet feelings from the original cast of the Bravo series, which is now getting a reboot.

On Tuesday (November 26), the network announced the Emmy-winning series Vanderpump Rules will return for its 12th season with an entirely new cast. Lisa Vanderpump, the matriarch figure and owner of several restaurants and bars staffed by the cast, will be the only original Vanderpump Rules star to return.

The stars of Vanderpump Rules were not told about Bravo’s plans to reboot the reality show’s entire cast for season 12, a source exclusively tells In Touch amid news of the upcoming season. “The cast members were left in the dark for months about the plans for season 12," the insider says. In Touch reached...