Hold on a minute. My read of this was that, while the SpC fee was indeed to be paid up front, it would be going to the GM or Mercedes or VW company, who then would be using those assets to fund their share of SpCs - I did not come to believe it would be going to TMC. Would be ecstatic to learn elsewise.
So it seems that you think that TM will release supercharger specifications so that other manufacturers can produce and install the superchargers -this is the only scenario which would include $2,000 going to them instead of TM.
I do not see superchargers ever produced and installed by other manufacturers. TM will continue manufacture the superchargers, install them and monitor the network usage, adding bays to existing or new locations so that the network develops to match the demand. The payment model (sharing the cost as Elon put it during the shareholders meeting) will be the same as it stands currently - $2,000 per car. The release of IP will cover all patents that make a battery pack able to work in tandem with the Superchargers.
There are several reasons why this arrangement will be preferred by both TM and the manufacturers buying into the system.
Other manufacturers are not moving into the developing and manufacturing of "200 miles+" EVs because it requires very significant R&D expense and team of engineers they simply currently do not have. To top it off
in their analysis this massive expenditure of capital has very high risk due to uncertainties of wide scale adoption of EV. As a result these manufacturers fall even further behind, and task of shifting to developing and manufacturing a compelling EV becomes even more daunting as time passes by. In this situation, if any of these manufacturers would be drawn in by Elon's offer of opening the charging protocol and allowing them to use TM Supercharger network, they will be happy to reduce risk by "outsourcing" and leaving the build-out and management of the supercharger network to TM.
From the TM perspective, it will be some time before other manufacturers can develop and start manufacturing the "200+" EVs. At that time the US supercharging network built by Tesla will be quite mature and undoubtedly cover all US, with probably more than 300-500 locations. Allowing other manufacturers access to these 300-500 TM Superchargers while Tesla car owners will in return gain access to the few that these manufacturers would build just does not represent a fair deal and will require some kind of monetary compensation to TM.
So I think that TM will open source all IP that is required for design of the supercharger compatible battery packs by other manufacturers and then allow them to buy into the already existing Supercharger network at $2,000 per car.