Every day, thousands of people are having conversations on GitHub around code, design, bugs, and new ideas. Sometimes there are complex and nuanced points to be made, but other times you just want to ???? someone else’s comment. We’re adding Reactions to conversations today to help people express their feelings more simply and effectively.
They also address part of the “open letter“:
While people have been able to include emoji in responses for a long time, using them as reactions resulted in a lot of noise. In many cases, especially on popular projects, the result is a long thread full of emoji and not much content, which makes it difficult to have a discussion. With reactions, you can now reduce the noise in these threads.