I think those statements moreso confirm that Masters is good supplementary material, but not defining of the entirety of the main canon, especially considering Pokemon's already existing branching timelines.
They confirm they make choices with approval, and the content absolutely deserves either their own profiles or keys, and might be good for justifications citing, but I'm not wholly convinced Masters is directly canon to all the games we've seen, in a timeline sense.
I don't think Masters should be disregarded, not in the slightest, but a CRT to discuss how much we use and for what keys is absolutely nessisary.