At the least, the idea sounds plausible - but that would be assuming that USPC consistently used the same style of opening strip during different periods in their history. I don't know if anyone's documented this over the years - for older vintage decks and especially for antiques, you're often lucky to find an intact box, never mind one that's still sealed in the original cellophane. That would understandably make documenting such changes over time a bit challenging to say the least! In fact, the oldest examples never had a box in the first place, often being originally sold in a simple paper wrapping.
There are other factors that can be taken into account beyond a tax stamp or a manufacturer's seal. One big one would be the exact design elements of the box. For example, we know that the "Standard" Bicycle box style for Rider Backs was used from 2009 to the present. There's all the small print appearing on a modern box of USPC playing cards - which includes a copyright dated during the year of manufacture (or perhaps the beginning of the following year, depending on whether or not there were some leftover boxes that needed to be used up).
For older boxes, there's other elements to take into account, though I don't know how much documenting of box style changes there's been over the years. There's also variables like reprints - a good example of this would be the "Bicycle 807" that USPC started offering last year for magicians who relied on the classic box design for certain tricks or for players who just like the old box better. It was in the classic "808" style commonly found in the 1990s and 2000s, with a barcode at the bottom of the box and no fine print about copyrights, but there was a number code under the brand name on the bottom of the box that began with the number 807. I never obtained a deck for myself to look at (and I'd really like to!) but in all likelihood they updated the information on the side of the box to show the place of manufacture as being Erlanger rather than the Cincinnati markings found on the originals.
There are many, many other design elements that can be factored in - I'm just not as well-versed in them as others would be, so I'll step back and let someone else share their wisdom, if they would!