So, am I right in my understanding that this is meant to add support for emojis not present in UTF8?
I believe it is an encoding for data into base 1024, using emoji as the symbol set. Similar in concept to Base64, meant to encode data into a format which can be sent anywhere ASCII is acceptable. This, one could think, would allow you to do the same thing more efficiently but with systems which accept emoji.
I'd expect that most places where emoji are accepted and reliably preserved, you could also use things like Han ideographs, which would give you a much larger symbol set to work with.
There's always base65536