Publishing basic facts like: "Mark Hamill was born 25 September 1951 in Oakland, California, USA" shouldn't fall under anti-discrimination laws. In fact, while looking up Mark's birthday for this comment, I noticed that IMDB doesn't actually post the actor's age. Sure, you can subtract 1951 from 2016 to get his age, but IMDB only gives you his date of birth. This is a fact, not a judgement call.
The problem that many people outside the industry are not aware of, is that IMDB doesn't post facts: they post anything that people submit. So actors routinely submit fake (older) ages for the competition, and IMDB's policy is to leave the "fact" up until it's proven false. This requires the victim to send IMDB a copy of their driver's license or other proof, at which point IMDB updates their page to their actual age. So basically actors are being forced into revealing personal information they don't want to reveal, and IMDB is playing a fairly large part. This is what I believe the original lawsuit that was the inspiration for this law was about.