A couple of things:
- VW already is paying for the SC network (that can be in the USA only);
Some of those are co-sited with Tesla superchargers, so yes, some site construction work and paying for grid supplies could be shared between the parties involved.
Nissan/Renault paid for much of the initial hardware used for the Ecotricity Electric Highway, until CCS was invented. They couldn't sell many cars without a nationwide charging network.
So, it's not unusual in any way for vehicle manufacturers to (part-) fund the installation of charging networks, and it's not unusual for some locations to have chargepoints from multiple charging networks.