@dansup @Gargron I was curious about this and so I looked at the code. The scoring for trending tags is not based directly on raw numbers of mentions but on the level of recent increase in mentions compared to historical norms. So to get a high trending score and make the boards, you need to see a big jump in tag usages over the previous day and not just have more tag usages than somebody on the board. Probably no conspiracy.

github.com/mastodon/mastodon/b

P.S. open source software is awesome