The 787 Battery monitoring issue has been fixed with the replacement of the BMU.
Has it?
I wasn't aware that the root cause of the battery failures had been identified. There are some hypothesis, and battery monitoring and charging algorithms are among some of the better ones. So this is a reasonable educated guess.
What this does accomplish is to reset the system reliability numbers back to those provided by analysis. The old battery failed Boeing's promised numbers by orders of magnitude. Plugging those into the requirements for ETOPS and it would have been a no-go. With a new unit, they get to start with a clean sheet of paper, with fingers crossed, hoping that nothing major goes wrong.
As long as the battery was failing 'quietly' (no smoke) , not much public concern was generated. In its nice metal box, this will be true again. Replacing units for low voltage lockout will be invisible to all but those concerned with maintenance and reliability. Will Boeing, the FAA and operators return to the status quo? Or will all battery incidents now be placed under a microscope?