"If you have your own boiler you will need the wall thermostat to turn the boiler/pump/valves on and off."
Why do you need a wall thermostat to turn the boiler on and off? Surely that's the whole point of a specific TRV doing a call for heat on demand. Otherwise, you would have to set the wall thermostat to the same temperature as each room.
My wall thermostat failed a few weeks ago and I've been running with TRVs alone since. I am in the process of replacing the wall thermostat though because of the increased accuracy in measurement, not because the heating stopped working.
The Tado TRVs don't communicate with the Smart Thermostat in my case. They communicate with the extension kit, which is connected to the boiler controls. The Smart Thermostat is wireless.
As mentioned, I have been using Tado TRVs without a Smart Thermostat for almost a month now since my thermostat broke.
If you are happy with the temperature control provided by the TRVs then yes, you could dispense with the wall thermostat.