That's great news as long as it doesn't mean a reduction in trains to London Bridge. It has seemed quite likely for a few years that two additional services to Crystal Palace should be possible in the Overground timetable, but it can be difficult to fit this with Southern services. It is possible that the Bermondsey dive-under and the reopening of platforms at London Bridge may make the paths between london Bridge and New Cross Gate a little more manageable.
And as somebody pointed out on the FH Soc facebook page yesterday, with Crossrail going through Whitechapel - providing fast connections to the West End, Paddington, and Heathrow - there will be even more demand on Overground.