The neatest outcome IMO would be to grandfather in data from before ~2022, but strictly require consent for anything new going forward.

Enforcement would be kind of impossible though. How would you prove the age of the data? And what about for things like websites - if a website from 2015 gets scraped in 2025, where does that fall?

So, maybe not a very practical solution. But I think the ideal outcome is one where AI companies don't have to throw away progress from the past few years, but artists have control over their participation going forward. It's hard to say if there's any solution that can respect both.

More likely than not, one party is going to be shafted; and it's probably not going to be the one with the money behind it.