It's mentioned in the 2014/94/EU directive on the deployment of alternative fuels infrastructure [0], see (26) and (33). It is not a law but it is a guideline for EU countries to implement it as law. And the countries that make up the majority of the EU's charging infrastructure plan on doing exactly that, so any delay would have put Tesla in non-compliance.
Furthermore, this 2021 European Court of Auditors special report pushed for the same [1].
A Supercharger station gives access to private users with an authorisation or a subscription so it's considered accessible to the public. All charging stations accessible to the public should to allow multistandard recharging.
2014/94/EU requires that public charging stations support a common technical standard, ie: CCS.
There is nothing in it that requires Tesla (or any other operator) to make their network available to all makes of vehicle.
However, without an "open" charging network Tesla cannot access government funds for charging network expansion that is available to their competitors.
So, I think the logic was: eventually it will happen anyway - so it's better for Tesla to do it themselves before they are forced to, so that they can do it on their own terms. For example, so that Tesla drivers will never have to wait longer than x minutes.
Still the acting Minister of Transportation in the biggest EU member state. That hair splitting is showing some lack of understanding how this stuff works.
I think Tesla saw the writing on the wall in the EU, which is that the EU doesn't want closed eco-systems, including payment, for EV charging. Now you can do it when forced or leap-frog that and get some positive PR from it. Plus you might be able to do it on our own terms. I highly doubt Tesla would have done it yet without some pushing from the EU.
Directly, no. Indirectly one cannot ignore the influence Germany has in the EU, so his word carries some weight, especially if you are a multi-national company operating in the EU.
That being said, Andi Scheuer is quite an incompetent idiot.
If I'm wrong, please provide a source.