if I understand it correctly, FontAwesome5 was rewritten from scratch and
existing FontAwesome4 icons were replaced by new ones.
So it seems to me that this update is not the same easy task which it was in
However, could you file a JIRA for this task?
I would like to propose to outsource FontAwesome5 into its own project.
If I remember it correctly, such a project just needs the FontAwesome otf
font files, a license file and an AS3 class that holds constants for each
particular icon name.