That is a different question. You are answering if the usual methods would authenticate it as an original. I believe you are right that they wouldn't. Thus it would probably be worthless.

But that makes sense. There are many modifications you can do with a card which will render them useless and no longer recognised as an original.

For example you can burn the card to ash. They would not be even detected as a pokemon card, but they are still an original pokemon card (if they were ever) which got burned into ash.