It is nice to see that while the thread does question some of Uber's motivation for the change, where there is a genuine problem with their product there is a frank admission (with quotes like "this is a common problem case we don't have an answer for yet" and "limitations of our current replication system are real, or we wouldn't have so many people working on alternatives") which people discuss seriously (asking for clarification and/or suggesting ways forward) rather than reacting with a knee-jerk defensive posture.
Provides a link to the rationale post from uber (https://eng.uber.com/mysql-migration/), and a tl;dr of it. Prior discussion here: https://news.ycombinator.com/item?id=12166585