Who's still running the node, please shut down your node.
you cant make new user stop his sync if you not remove the wallet from website, and im sure controll all people to shutdown or turn off his wallet is very hard, this is decentralization system, no one cant stop it, better you find other way maybe with make new version of wallet and including new setup (block), and announce to all user to upgrader his version
I think wallet and node is not the same thing. Rather any wallet can be node but not each node is standard configured wallet. at least in BTC it are so. If run wallet at other port with different config it will full node . Correct me if I am wrong