Does Xfinity Support Family Set Up for Apple Watch?

My 12 year old son does not have a phone, but we would like to get him an apple watch SE and use Apple's family set up feature to attach it to my phone. I understand I would need to add the $10 monthly cell line to the watch and the watch must be cellular ready. A couple years ago I asked Xfinity about this feature when it was new from Apple and the response was that Apple "Family Set Up" is not supported at this time by xfinity. 

My question is Apple Family Set Up for apple watch supported from Xfinity now? If not will it be?

Because I am about ready to change service providers over this feature if xfinity won't support it. I would rather my younger boys not have mobile phones, just a watch to call and text.