I don’t think this is a major “this is why people pirate”. Pirate sites also regularly get cracked (possibly more often the the average streaming service). It isn’t like bank details were leaked here so the only real difference is that in some pirate sites you don’t need a login at all.

Unclear whether they were hacked. A followup says:

We [Crunchyroll] have […] investigated the situation, and determined that there is no evidence that Crunchyroll’s systems have been compromised

They may have been fished.