Since they don't "own" the data they lost, only "rent" it, they probably have to be seen doing something about it, lest they face the wrath of record companies.
I have a really hard time imagining the record companies giving a shit about this, this isn't a pre-release leak. All the valuable content is already freely and easily available for download on the internet.
It's performance art all the way down - it repeatedly states they are not happy about piracy and will come after anyone doing it.
This isn't aimed at pirates as much as it's aimed at non-pirates, especially companies with significant assets.
They know full well pirates don't care, but it's a message to any company or entity seen as "too friendly" with pirates or that enables pirates to do their thing.
I doubt anyone in the industry really cares at this point, and in the end it's a rather small group of massive companies whose opinions Spotify cares about.
The PR of being "hard on pirates" matters a lot more than any losses they may take, imagined or otherwise. I just hate how fast courts will act on this compared to matters of literal life and death.