No, there are no plans to change the structure of data access. There are other projects out there that use OR Mappers if that is important to you, I have my reasons for not using an OR Mapper in mojoPortal.
The data layer is an evolving API. Interfaces are not supposed to change, it would be cumbersome to keep creating new versions of an interface for every new or changed data access method.
Most people developing with mojoPortal are only using a single specific database. If there is a "burden" to maintain different data layers and build packages that burden belongs to me.