It seems like they acknowledge that Threads is part of the mainstream though.
Mainstream Social Platforms: A Less Hospitable Arena Every Day
Instagram and Threads downrank “political content” in their algorithms
And also not fully counting Threads as part of the fediverse, as per,
Threads ... has adopted the fediverse, ... as they build towards full integration.
Moving on,
And touting "15 years of the fediverse" while ignoring for all but a year it's been lemmy.ml
Uh, no. Mastodon was on ActivityPub before there was a Lemmy. And 15 years takes us back to 2008 - so they're counting the pre-ActivityPub and pre-"fediverse has been coined" days too: as per https://www.britannica.com/technology/fediverse there was the OpenMicroBlogging protocol back then.