If your 311 is currently active, then that is the cause of the message as they are being phased out in favor of vip211’s or Wally’s. 722’s are considered old but not completely obsolete, if you would still like them upgraded then it would depend on your needs.
Is each 722 running 2 separate TV sets? Is it posible to have a coax run from the home to the shop or are they on separate satellite dishes?
Ideally, you would upgrade to the latest Hopper3, and add a Joey per every remaining location. The way these work is that the Hopper is the brain of the system, it does the satellite reception and DVR duties, among other things, then it transmits the video to the client devices, aka Joeys. The Joeys cannot run on their own, so if there is no way to connect your shop to the same network as your home then you will be looking at a second Hopper or a standalone receiver like the Wally.