I'll retract my opinion that "hate speech is down" as it's apparently difficult to measure but I am going to continue to say that "hate speech is up" is at the very least "highly misleading" as it gives the impression that the platform is worse for minorities than it was pre-acquisition. The reverse is the truth, given the lower impressions of hate speech, it effectively means that those that would verbally attack minorities are being highly squelched versus the situation before the acquisition. That's all around a good thing.
The visibility of hate speech on twitter is down.