In message .com,
TheOneKEA writes

Is this platform planned to be brought into use by TfL as part of any
new Overground services to Clapham Junction?

I think it will when the East London Line Extension reaches Clapham
Junction. The likely scenario seems to be that London Overground
services running anticlockwise (i.e. on the ELLE) will use platform 2,
while those running clockwise (i.e. on the West London Line) will move
across to platform 1, thus offering cross-platform interchange.

--
Paul Terry