Could they still use it on the only Judy in P6?

The nude version of Judy is required to decrypt EJ's geometry.

The same goes for any other item (free or commercial) that requires P4/P5 files not included in P6 for decryption. And even those that are included will present some final roadblocks, since they're all compressed now.

The merchants are just going to love this, once they realise the implications ....