I have a client who has some ArcGIS Desktop 10.0 installs and they were wondering if they can connect to a 10.2.1 Geodatabase. The 10.0 Client and geodatabase compatibility—ArcGIS Help | ArcGIS Desktop has an entry for 10.0 connecting to a 10.2 Geodatabase, but not 10.2.1 (either through Direct Connect or SDE service). Which is probably correct however I have seen errors in the documentation before and want to check that this is correct or not.

My client is also thinking about moving to Oracle 12c, which I know is not supported, but I need to know that if they stayed at Oracle 11g then they could still connect.
Has anyone configured and successfully tested this configuration?
cheers.