Southern Customers Services department informed me that Southeastern will operate all trains between Peckham Rye and Victoria in the future and Southern will then no longer operate the Victoria route.

However, it is the expectation that the East London Line will stop at all stations to Clapham Junction. London Bridge passengers will have to change at Peckham Rye for Clapham etc.

I take this to mean that the Victoria loop that goes from LB to Victoria via Forest Hill will cease to exist.