As has been said, the reason is: - the origination where the ROM dump would come from is eminently traceable, which matters because - Namco, Midway and them go WAY back - and also that they're trying to do it the right and legal way, which will take a long time and potentially fail
If it was a long-lost prototype that the original developer LOST (ex: Bouncer) then this would be less of an issue...