I think after they crippled some earlier cars and some refused updates, Tesla required a security update in 2020 that stated they would disable features if you didn't update. Earlier years probably had no reference to "mandatory" updates, but my 2020 Owner's Manual states:
"Note: The software update window persists
until you install the update. You must install a
software update as soon it becomes available.
Any harm resulting from failure to install a
software update is not covered by the
vehicle's warranty. Failure or refusal to install
updates can cause some vehicle features to
become inaccessible, digital media devices to
become incompatible, and can limit Tesla's
ability to diagnose and service your vehicle."
This is the only "urging" to install an update I am aware of.