Don't we already have pretty robust laws when it comes to person's likeness?
I presume most contracts cover this aspect mainly for the purposes of marketing and future references. Of course the actors probably didn't expect the extent the current technology could allow their likeness to be exploited.
It would probably make sense to require more specific contracts for this purpose, and have previously signed general contracts become insufficient for using actors' likeness for this purpose.
They say they are expected to accept contracts that were designed for the old business model while the industry structure and technologies have changed. Here's some video of the speeches & demonstrations.
It's not really that complicated if there's a will and resources to investigate. You can legally compel someone to produce evidence or show you how they do things whether it's in an Excel file or in a paper ledger.
Conversely, you can burn a paper ledger just as easily as you can delete a computer file. In fact computer files might actually be more resilient since they can be recovered if not properly destroyed.