No. The press as usual are talking through their backsides.
The batteries on a 787 do the same job as on any other airliner, the difference is that because the control systems (I do not mean flight control specifically) rely so heavily on electrical power that in the event of a total main power loss the battery will need to last a while and keep lots of computers running.
The flight contol surfaces are still powered by hydraulics in the usual way.