Yes, it is true. His attny can file the divorce papers and have you served (and you will be required to respond in twenty days). If your H is telling you the attny cannot talk to you there is a good chance he has retained counsel.
Start making calls today or first thing tomorrow and get some consults lined up.
Do not listen to a thing your H says and I would tell him flat out that you will NOT be discussing any legalities with him. Period.