How does adding a non-existent section of dual carriageway "align" the geometry of the junction?

Unless TfL have installed a physical barrier between carriageways very recently, the only separation between the traffic island at the junction with Woolwich New Road and the crossing island at the traffic lights is by painted road markings.

Is there a TomTom originated MapRoulette challenge actually asking users to tag for the router by adding dual carriageways where no physical separation exists?

https://wiki.openstreetmap.org/wiki/Dual_carriageway
https://wiki.openstreetmap.org/wiki/Tag:dual_carriageway%3Dyes#Bad_mapping