I don't see how it's relevant. The counterfeit adderall being sold isn't pharmaceutical grade meth. People buying black market sealed bottles of adderall would probably want to know that it's likely not adderall.
The author is preying upon readers' cultural understanding of meth (via the news media and shows like Breaking Bad) as something inherently dirty, something for which there is no possible safe usage. The existence of FDA-approved meth ruins the framing even if FDA-grade is not what a buyer would be getting.
There are very few situations where prescribing methamphetamine is reasonable. It's a niche drug. Even XR formulations of Adderall are considered a blunt instrument compared to more recent alternatives.
The issue is one of trust, integrity, and safety. Pharmacies should not operate like drug dealers.
XR is obviously preferable to IR, but amphetamines have been falling out of favour over the years (it’s a slow trend). Vyvanse, NSRIs and even SSRIs tend to be regarded more and more favourably compared to amphetamines (Adderall) and methylphenidate (Ritalin).
(Disclaimer: I myself take Adderall XR 10mg as prescribed, so I have the opposite of a conflict of interest in this context.)
... changes nothing. If you don't expect to be getting meth, you shouldn't be getting meth.