It looks like the back office version of Oyster won't be implemented until at least 2018.

The remaining phases of the Future Ticketing Programme a

"Phase 3
Travelcard season and bus passes available through contactless bank cards

Phase 4

Phased adoption of technology platform resembling contactless payment to deliver 2nd generation Oyster

Phase 5
Decommissioning of current Oyster platform, once migration to 2nd generation is complete"

The December 2015 TfL board papers contained this update:

"Phases 3 and 4 were given full authority in July 2015. We have defined Phase 3 requirements and started design and development. We held Phase 4 workshops with our contractors to ensure we have a fully aligned set of
business requirements and design solution allowing development work to start. Following customer research for the mobile ticketing app, we have produced prototypes to inform the design. Phase 5 is planned to commence in 2020.


Actual date:
Launch of Phase 1 of the ticketing app
22-Dec-16

Availability of weekly capping for Oyster
customers
22-Dec-17 "

which suggest that Phase 4 would be implemented in 2018 or 2019.