Every number here is a rate of change, never a total. Size is not news. The largest repository on GitHub is not rising, it arrived years ago. What this looks for is movement, and specifically movement that more than one unrelated source noticed on the same day.
That second condition is the whole method. Stars can be bought, backlinks can be built, app installs can be farmed. This project has already killed 2,601 domains for sitting inside link networks, one of which ran to 2,046 sites and covered 98% of everything it tracked on .it. All of them were manufacturing the exact signal one of these sources measures. Faking two unrelated signals at once is far harder work, so a repository seen moving by GitHub and HackerNews, or an app seen by the App Store and Google Play, counts for more than a bigger number in one place.
Whether two sources are genuinely independent is measured rather than assumed. Majestic ranks domains by backlinks and Tranco ranks them by traffic, and the two were treated as one voice for weeks. Comparing their daily movement across 83,000 domains showed no relationship at all, so they now count as two. Any pair that turns out to share data underneath gets folded back into one.
Entries are written to be read rather than scanned. When the evidence is thin, or the story behind it does not hold up, the entry is left out rather than published with a caveat.