All of your "interpretations" are technically incorrect because there is nothing in the statement or context (as you've described) to imply any of them. You shouldn't read more into the statement than what it actually says.

That said, your proposed statements are often true, so most analog-to-digital image captures do benefit from some sharpening. Also, interpolation is inherently "blurry", which sharpening can counteract to some extent.

All of your "interpretations" are technically incorrect because there is nothing in the statement or context (as you've described) to imply any of them. You shouldn't read more into the statement than what it actually says. That is not to say that there is no underlying reason for the statement, just that you cannot divine what that reason is.

That said, your proposed statements are often true, so most analog-to-digital image captures do benefit from some sharpening. Interpolation is inherently "blurry", which sharpening can counteract to some extent.