Regards esteemed friend @felander.

what do you think?
good news or bad news?

Definitely all actions that neutralize or at least mitigate criminal acts will always be received as good news.

We have always heard about the anonymity of BTC and the way in which it can cover up criminal acts.
The truth is that BTC is not "anonymous" but is "pseudonym". Therefore tracking is possible. although as you very well you say it:

We all know this will be a slow process but every event like this is one in favor of the HODLERS.

Fortunately there are cybersecurity startups such as Chainalysis are dedicated to using blockchains such as Bitcoin to prevent human trafficking or child abuse.

“Chainalysis Inc. became a member of the IWF on August 1, 2016. They support us in our goal of eliminating child sexual abuse online.”
_{Internet Watch Foundation (IWF)}

Your friend, Juan