Apple Watch Reward and By The Gig plan

I've seen only in these forums a member saying that to activate the Apple Watch via the Reward ($300 back on a $300 watch, if the SE Gen 2 - perhaps $300 off a more expensive Apple Watch if one desired) one must have an Unlimited Data Plan from Xfinity Mobile.

I don't see that in the specs anywhere about the Reward, the Watch, or see anything that says one cannot have a "By The Gig" plan. Oddly it says the Watch plan would automatically be "unlimited" data usage, but that data usage would go against the Xfinity Mobile Cell Data plan for the phone.

Does anyone know if an Unlimited Data Plan is actually required? Perhaps the other forum member was merely noting that wearing the Watch and using so much cell data would make it imperative to have an Unlimited Data Plan. My thinking is I could have our "By The Gig" plan, and like we do with our phones, only turn on Cell Data for the Watch occasionally, keeping under the By The Gig limit...

thanks

Rich Apple