Ok, let's take a step back then.
When you successfully publish a map service, is data being copied up to the GIS Server in the service definition, or is the data remaining 'referenced' in the database?
Essentially, is the Oracle database successfully registered with the GIS Server?
All things equal, I suspect that you're copying data up to the server, and that's why map services can be published. Feature services require data referenced in an EGDB, and unless you have a server managed database/hosting server configured, feature services won't publish.