It doesn't, no. The bot gets its data from another bot, at https://lemmyverse.net/, which only crawls Lemmy and MBIN instances at the mo.
We'd either need to send a PR to get that bot to crawl PieFed instances too, or just replicate the functionality from the same machine that runs 'tcbot'. Communities would also need to provide their 'active users / month' too. It's just the subscriber count currently, but it shouldn't be too much of a problem hopefully.
I've complained about the 'trusted instance concept' too ... I've a horrible feeling that it exists to protect piefed.social from the DB bloat it inflicts on everyone else, lol.