Monica Chew, the engineer who did the bulk of the work on this feature, did consider a number of available lists before settling on this one. The Disconnect list was the best freely-licensed (GPL) one at the time. Also, they now have a web form to let users suggest new trackers to block (https://disconnect.me/trackerprotection) so it should get even better.
> Does anyone understand why Mozilla publishes valuable information like this over random personal blogs, rather than a central place like a knowledge base (e.g., a wiki)?
It's pretty tricky to share information in the "right place" because of the amount of information produced by everyone at Mozilla. Someone's preferred channel is often another person's blind spot.
In this particular example, all of the information is on the wiki page I maintain (https://wiki.mozilla.org/Security/Tracking_protection) but it felt like a more accessible description of the overall system would also be useful. I put it on my blog because it seemed too detailed/technical for my team's blog (https://blog.mozilla.org/security/) or Hacks (https://hacks.mozilla.org/).