Recall thermostat sensor replacement and radiator flush

Car dealer is replacing thermostat sensor under the recall by Ford.
Can you tell me if a radiator flush should be included in the sensor replacement recall or should it be done separate?

Since we bought a couple years ago and just had it in for tune up, the dealer recommended a radiator flush as part of the maintenance. I understand that is normal and fine with that. My question is, should the dealer charge us for a flush since they will be replacing the thermostat sensor at the same time, which is under recall?

They are charging us separately for the radiator flush and I'm just wondering if that is legit? Or should the flush be part of the recall thermostat replacement?

Just trying to make sure I'm not being messed with and being charged for something that is part of the replacement process.

It's late, so I hope I'm making sense. Thanks for your input and guidance.