Drop rates being broken actually happens quite regularly, most players just don’t notice. It’s always treated as a hush job, there isn’t any official acknowledgement unless there is absolutely no way around it, there isn’t any information once it gets fixed, the only viable answer for anyone bothering to inquire amounts to “we didn’t change anything”. The most recent example is [Not a bug] Adventure Board misconfigured for Traitstone tasks, I wouldn’t be surprised if anybody doing a task analysis over the past three weeks would find that distribution rates have changed significantly, despite “everything working correctly”.
I guess there are some legal consequences associated to admitting such mistakes. Like the few times event chests were actually unable to pull the kingdom mythic, as the grand prize in their gasha system. I just wish it wouldn’t make trying get these type of issues fixed such a miserable job, there’s a huge amount of effort involved to report it accurately enough to be considered beyond doubt, and the only official feedback you’ll at best get is that you are just imagining things.