Usually a "right" defines a grant of legal ability to act, that is illegal for a third-party to attempt to constrain.

Examine the right to free speech:

• it is a denial of your rights if a third party interfere with your exercise of your free speech (by e.g. forcefully "silencing" you in the public square—maybe using noise-cancelling speakers or something.)

• It is not a denial of your rights if you made an agreement with the third party that they would aid you in your exercise of your free speech, and then they choose to stop honoring this agreement. (I.e. forums are allowed to ban people.) This is, in-and-of-itself, a consequence of the right to freedom of association.

I would expect the same to apply to the "right to repair": Tesla is allowed to revoke its complicity in helping you drive its cars—by "bricking" them—but you then have a right to circumvent that bricking, and they would be infringing on your rights by trying to prevent you from doing so.

They don't have to make it easy; logically, with a highly-complex software system like a smart-car (that hasn't gone through an ecosystem-wide standardization like PCs have), the vendor's complicity is required to make doing anything at all with the car easy, and they're not required to give you that complicity. (Consider: even if the law required them to, they could always just go out of business in response, like Lavabit did.)

But once you start "hacking your car", anything they do in response to that to inhibit you would be a violation of your right to repair.

A challenge about journalistic summaries of court decisions is that the court decisions usually address only the application of one area of law. (Also, they are often not even making a final decision, although this particular decision is final on this issue.) Here, the Supreme Court was considering whether a patent holder can assert that a patent lets them prevent some activity with respect to a patented product even after the product has been sold (in this case, when a consumer sells a patented printer cartridge to a remanufacturer who refills it with fresh ink and resells it to another consumer). The court said that existing patent law does not, in fact, include a right to prohibit this activity.

However, this is not the same as finding a blanket right to repair things; there might be other legal reasons why manufacturers can try to restrict repairs. The court did not decide whether any of those other reasons are or are not valid. One example that comes up a lot and that some of my colleagues are actively working on is software copyrights, and particularly §1201 of the DMCA as applied to embedded software.

It's also worth remembering that most U.S. court decisions that examine parties' legal rights are interpreting statutes or contracts (whose text can potentially be changed in response to the court decision), not evaluating constitutional rights (which are difficult to change). So a lot of decisions that say a party has a right to do something mean to say that a particular law or contract did not prevent the party from doing it. But another law or contract—including a future revised version of that same one—might conceivably still prevent it.