> If React didn't have an explicit "grant" there would be an implicit grant.
Please provide a citation to any court decision so holding, or to the text of any law that clearly implies this.
The reality is that a couple of lawyers have come up with the speculative theory that maybe, some day, a court will read the plain text of the BSD license as granting an implicit patent license because some of the words its uses are kind of similar to the words used in a seemingly unrelated law.
This theory is...tenuous at best. More to the point, it's just a theory about what a hypothetical court might rule one day in a hypothetical case. (Plus, I mean, hypothetically the court might rule that an explicit grant can't limit the rights granted by an implicit grant in this case. Since we're just speculating about what new rules a future court might hypothetically make.)