I think they should have not reinvented the wheel ;-) and use dCBOR42, which has an actual canonical form. But somehow people like to use json in places where it's shown again and again it's a terrible choice.
The reason Social Media protocols need to be kept simple is precisely for this reason. Getting developers to all agree on things is next to impossible. So the way to combat that is by removing all those "things", and go with the simplest design that's workable. It's almost like politics in that it's "The Art of the Possible". And to be "possible" in this context means universal acceptance.