The Oxford Comma isn’t a “mistake.” It’s the preferred style for many people, and it’s both correct (assuming it’s used consistently in a doc) and common. It’s

The Oxford Comma isn’t a “mistake.” It’s the preferred style for many people, and it’s both correct (assuming it’s used consistently in a doc) and common. It’s difficult for me to understand Google or any other entity to enforce an arbitrary set of grammar style policies on third parties except when the product is a journal, magazine, or something to that effect.