These spammers also spammed threats to Codeberg users that maintain projects that advocate for human rights, trans rights, etc and collect facts/data against hate and discrimination. The content of those threats are how we know those spammers are far-right forces. The spam email notification was just a side-thing the spammers did to get more attention.

These forces made spam accounts that spammed threats/insults in issue trackers and pull requests on projects that collect facts and resources against hate and discrimination and advocate for human rights, trans rights, etc on Codeberg. Some of the same spam accounts were behind the spam notification emails.

Also, because of the timing of the DDoS attack, they are likely be behind the DDoS attack as well, although that's not for sure. So we know they're far-right forces because of what they said in their threats to Codeberg users. The blog post mentions this but doesn't explicitly list the projects that were threatened so they don't continue to get spammed.