I think Starlink is going around making deals with mobile providers in different countries. T-Mobile is the one for US, Rogers is for Canada, and I remember seeing one recently for Australia.
They are on the front foot and going for it before the service is really ready for prime time. 3gpp has working groups that is working on defining standards for direct to device satcom/5G NTN (non-terrestrial network). Chip makers are implementing it in their silicone etc. The rest of the industry is a bit on the back foot. It has not been a very competitive market the last decade, but it's burning under the other players foot now and they need to consolidate and turn them selves around before SpaceX eats all of their lunch. D2D could be a valuable revenue stream, but not if SpaceX gets there first. Interesting times.
In New Zealand they've partnered with One NZ (Vodafone) for mobile starlink.