I had heard that another Victoria-Dartford service but via Sidcup might happen too, to get it to 4tph.
Victoria-Hayes could also work well in a future where Victoria Eastern only runs metro services, and the need to increase Vic - DH/PR - Lewisham core frequency. It'd be pretty slow though - most people would go for the Charing Cross! This is assuming no/not yet re Bakerloo.
They definitely want to do some investment / subsidy from developers on the route. I know the Old Kent Road is earmarked, and Lewisham of course, but other places on the line should definitely seem some intensification/lighter TOD closer to the stations. Doesn't have to be Blade Runner - but a few mid sized developments. Beckenham centre itself could see a bit of a building boom, if that has the tube it'll be very well connected: Bakerloo, Southeastern Vic/Orpington, Southern locals via Crystal Palace, and the tram into Croydon. Might become a much bigger interchange, even see some semi/fast calls?