No, that's your interpretation - not what any court has determined. I would argue that direction from the NIH, CDC, Virginia Department of Health, and/or literally everyone's current doctor constitutes "the advice" needed under the law.
Not a single court on the planet right now would be so idiotic as to side with your interpretation of that law.
Section iv.) says "upon a) or b)". a) says "carrying on his person an affidavit from the physician"; b) says "the declaration of a disaster or state of emergency by the Governor in response to a public health emergency where the emergency declaration expressly waives this section, defines the mask appropriate for the emergency, and provides for the duration of the waiver"
It's quite clear. Section ii.) gives much more wiggle room; you could cite the NIH, CDC, etc. there. Section iv.) says only the Governor's declaration (with very specific requirements the current emergency declaration doesn't give) or an actual physical affidavit you're carrying with you count for its exemption.
https://law.lis.virginia.gov/vacode/title18.2/chapter9/secti...