Board Thread:General Discussion/@comment-24934890-20180911200208/@comment-27312496-20180915213914

You're grabbing at straws to try and support this theory. There are a number of reasons for Ruby to have given the name of her mother rather then her father. They could have been lovers but never married. They simple kept each others surnames and Ruby was given her mothers. Obviously in-universe Ruby and Yang having different surnames doesn't isn't problem.

You've yet to explain why Ruby and Yang are being kept in the dark about this. Why are Tai, Qrow, Summer and even Raven keeping it a secret from them?

In the end it doesn't matter what subjective points you bring up, Word of God has already disproven it.