Congrats, Eric for getting the PL descriptor! Looking forward to seeing it. Obviously, the reflective fields would be obvious to someone seeing the coin in real life, but it is really nice to have it as part of the grade as a photo might not capture it so well.
I agree that calling a prooflike coin a "variety" is just wrong. But I think NGC is using the term proof like simply to describe a circulating coin with unusually reflective fields and it is just a description of the appearance. The amount of "reflectivity" needed for the PL destination is of course subjective and depends on the opinion of the grader but then all grading by a TGP is subjective. Descriptors like PL also indicates that coins of the same "grade" can differ significantly in value and desirability despite the impression often given by TGPs to the contrary.
From NGC website:
"Most circulation issue coins have minimally reflective fields, even in Mint State (MS) grades. When a circulation issue coin’s fields exhibit a higher-than-normal degree of reflectivity, the coin is said to be “Prooflike” (or “PL”) because it is reminiscent of a Proof coin. If the fields are deeply mirrored, the coin is said to be “Deep Prooflike” (or “DPL”).
NGC uses the PL or DPL modifiers after an MS coin’s numeric grade, when applicable. These designations indicate only the degree of reflectivity evident in a coin’s fields and make no implication as to other qualities associated with Proof coins, such as frosted devices and superior sharpness."