Blocking variations.brave.com which is used for A/B testing could potentially break Brave's functionalities. For me did Brave's "forgetful browsing" feature broke which seems to be disabled by default if you block this domain.
I'll be the one to stay on topic instead of joining the omgchromebad crowd.
My question/concern would be, why would a browser need to connect to an outside source in order to Forget your browsing? What would it need to reference?