The article starts by pointing out that Rivian has chosen to focus on their own network locked to just their own vehicles rather than backing a wider play like Electrify America. The concern is that because it is working for Tesla to have their own proprietary network, we'll see more incompatible networks proliferate rather than fewer more general efforts like Electrify America.

Given Rivian uses CCS1, the federal (or a state) government can mandate pretty easily that they support all cars tomorrow after the fact.

That's a bit more tricky for Tesla.