You cannot go backward to what simply did not exist in the past.
Most Civil 3D Styles will go forward with only occassional minor problems, but nothing in a Civil 3D drawing model can go backward with actual functionality.
Our Framework for Civil 3D products always support multiple releases of AutoCAD Civil 3D.
Remember that Making the Data is not Publishing
In many cases the Civil 3D "feature" Data can via LandXML, Survey Dbs, and other exports.
Dumbed down representations of Civil 3D features as AutoCAD primitives can.
Most certainly DWF, PDF, and other picture variants can.
Civil 3D like most modern software is continuously developed.
In AutoCAD Civil 3D, some of the Features their styles and their properties change with each release.
The functional power in model-based software comes from its synergistic and interconnected whole.
This is as true for Microsoft Word as Civil 3D.
The parts are "smart" and "talk" to one another and just like English, the langauge is changing slightly all the time. Dig?
It is a misconception to believe that software developers do it this way completely on purpose. The process of creating modern model-based (object oriented) software, the available development tools, time, and money make it a certainty.