No. No version of Revit is backwards compatible.
I have read, though I have not tried, that you might be able to export the model to another format, and then re-import into a previous version. However, it's a messy process and errors are likely.
It makes me want to start using another program.
Autodesk is obviously restricting/punishing users because it suits the Autodesks "business model" more and might forse upgrades. It does not forse upgrades, it makes whole projects say on early versions.
I think it is wrong, opportunistic and greedy and it will do more damage to the business model than create benefit for Autodesk.
And before anyone starts with the functionality issues of backwards compatability......look at every other program in the world that does it with a simple warning during the process.(including Navisworks and 3DS Max)
It's not the real deal, but you're able tu re-use some data.