the source blog post: https://blog.twitter.com/en_us/topics/company/2021/rml-polit...
"In six out of seven countries — all but Germany — Tweets posted by accounts from the political right receive more algorithmic amplification than the political left when studied as a group."
My guess is that when you ban, kick, make unwelcome people on the right, the algorithm has less content to distribute, so the content that exists gets boosted more.
Just a guess..... I doubt they are boosting the daily stormer.
My initial guess would be that the algorithm wants to boost engagement and people are more likely to engage with posts that make them angry. So if Tweeters tend to lean left, they would be more angry with (and therefore, engaged with) tweets from the right.