It may have been inevitable that this or something like it would happen, because the astrological community has a long history of making extralegal claims on factual information. Many algorithms have been published in books with copyright notices claiming that if you implement the algorithms, then you can only use the resulting software for non-profit purposes. That's a transparent attempt to claim software patent protection (inherently questionable already) without having a patent at all, using copyright law as the basis instead, so as to get the much longer term and lack of review applicable to copyrights instead of patents.
Information about the circumstances under which a specific person such as a celebrity was born ("data" in the technical sense of the term as used by astrologers) is obviously factual information: it has no creative component, I don't have the option to use someone else's "interpretation" or one I might create myself instead of the one correct one if I want to erect a natal chart for the person involved, and this kind of information quite reasonably is not subject to copyright claims. But publishers of astrological databases make not only the (highly questionable) claim of "database copyright" on their compilations, but also on every individual fact therein. If you cast a chart using an item of data from a commercial database, it's claimed that you incur obligations like buying a more expensive class of license should you publish your chart commercially. And the damned thing about it is that the astrological community has for decades accepted and propagated these kinds of claims, giving them a sort of legitimacy that's independent of their legal validity or lack thereof. Read the copyright notice to any popular astrological software to see the list of absurdly overboard copyright claims by predecessors that the authors of the current software are trying to obey.
Given that people in the astrological community not only routinely make such claims, but also routinely treat such claims by others as legitimate, it's no surprise that Astrolabe would file the lawsuit they have. It's quite likely that just like anime fans with "legal fansubs," and just like Harry Potter fans with "fiction can't possibly be child pornography," Astrolabe truly believes that the customs of their community actually are the laws of the broader society; and then it's no big surprise that they found a lawyer willing to humour them on that point and take their money. The best outcome of this case would be if Astrolabe could fall hard enough for it to be a wake-up call to the astrological community that overbroad patent-masquerading-as-copyright claims really are not the law and should not be taken seriously.
It is largely because of this kind of nonsense that most of the astrological software I've published is public domain, whereas I'd retain copyright and use a free license for most other kinds of software. There are too many, and too broad, copyright claims in this community already and I don't want to add to the mess.