I couldn't find anything about that. New regulations regarding GDPR are getting increasingly common.
I want to protect the privacy of my users as much as possible and I don't need Firebase Analytics to get insights, so I'm thinking of removing it. It'd be a problem tho if it's a secret ranking factor in the Play Store. I already know that AdWord conversions won't work without it.
Does anyone of you know? Maybe some Googler here? :-)