I think the market forces point in the opposite direction. With the big regions EU and China having standardized charging, they each created a market for different open charging networks to compete in.

In e.g. Germany Teslas are <10% of the new EVs sold YTD, I doubt it would make much sense for Tesla trying to maintain a Tesla-only network there, as they have to support the standardized connector and communication protocol anyway. They can only gain by opening up their charging network there.