Tesla, like almost any other car manufacturer, makes most of their revenue and profits from selling cars. Their charging stations bring very less, if any, revenue. If my assumptions are right, then why would tesla give up their moat (charging stations).

Marketing

Allowing all EV drivers to use Tesla charging stations can be good marketing for Tesla. Tesla EVs are the only EVs (these days) without a waiting list. Maybe opening up charging stations can help market and increase demand for Tesla vehicles.

Charging was never a moat

Tesla CEO mentioned recently that (always coming soon) full self-driving capability is responsible for Tesla’s monster market cap. IF that is true, then charging stations can’t be a significant moat. Any EV manufacturer can build a facility to charge vehicles. All they need is land and electricity (I know it is much more complex than that).

If charging stations aren’t moat then Tesla doesn’t lose much by opening up their charging stations

Vision 420

Opening up Tesla’s charging stations might be one of Elon musk’s visions and his minions might have raced at full speed to get this deal done.