Hey!
I personally wouldn't worry too much about it being a few months old. Firms are usually more interested in how well you understand and analyse the development rather than whether it happened in the last couple of weeks. Something like Getty Images v Stability AI is going to have a real impact in the IP sector, so I'd say it is perfectly fine to discuss it in relation to ongoing questions about how copyright law applies to generative AI.
As a rough guide, I'd say that anything from the last 6-12 months is usually acceptable for interviews, especially if the issue is still evolving (which AI regulation definitely is). Of course, the more recent the better it is, but I'd pick an idea that you can discuss in detail over one that is the most recent