The only reason to upload a Revit model the current version of A360 is to view it, since central files can not be hosted here. There's even less reason to do so given the extremely limited nature of the current viewer.
When you upload a revit model to A360 the integrated viewer allows you to look at both the model in 3d as well as the sheets included in the model. Both of these are nice addon features but ultimately the viewer has little use in it's current iteration. Allowing users to mark-up/comment on specific items on the sheets (and permanently tying a comment to the user that made it) on the otherhand would be incredibly useful.
Further, Revit integration for comments, similar to Autodesk Design Review, would massively improve the usability of the entire A360 concpet. Outside users (clients) could login, open the viewer, and add comments that production staff working in Revit could automatically see and react to.