It was a (very) long road as you can see from the link above.
In my opinion, I don’t understand why a bisexual pride flag emoji (or an asexual pride flag) is not under consideration by Unicode. For what it’s worth, our proposal as architected was meant to be compatible with any additional pride flag symbols to be added later on, ie, it was not locked in to one specific flag, and why should it be?
There is an unmistakable power of a flag to make a person, a human being, feel like they belong, as a person, in this world. (See: Photo Friday: The remarkable power of flags to create a culture of acceptance).
If computers with the capacity to launch people to other planets can’t be purposed to support this simple task, are we using them for the right things?
More than 10,000 people have signed a petition for the emoji.