Tunbridge Wells was only going to be peak only via London Bridge anyways, and that's still going to happen. It will be a "via Elephant" service that gets cut as a result.
You seem have misread what I wrote - I did not suggest that trains from Tunbridge Wells were via Elephant and Castle at all. Here's the logic:
Originally, there were to be only 6 trains per hour up through E&C and
then through the core. These were shown back in 2011 (London and SE RUS table 5.2) to be pairs of trains from Bellingham, Sevenoaks, and Maidstone East.
As of yesterday, they announced there'd now be 8 trains this way, of which 4 would be from the Wimbledon loop. This therefore required them to
lose 2 trains (from the earlier proposed 6) from the E&C route through the core. The DfT announcement showed that these were the Bellingham pair, going by the explicit inclusion of Sevenoaks and Maidstone East. Hence, no further cut of a 'via Elephant' service is possible as you suggest.
So we now have eight trains up and through the core via E&C, therefore we also have to
lose 2 trains from the previous 18 tph via London Bridge, because we still only have the 24 tph total available capacity north of Blackfriars.
I suggested they might lose Tunbridge Wells only because people in that area have been opposing diversion to Thameslink.
However, as
Class377/5 then reminded us in post #36 above, it looks like the longer distance SE origins of Tunbridge Wells and Ashford had already been negotiated away beforehand (replaced by Dartford and Orpington) - so the possibility (of removal Tunbridge Wells) is overtaken by events anyway.
Edited to add:
I hadn't taken this on board earlier, but the prior abandonment of Tunbridge Wells is signposted in the Thameslink/Southern franchise consultation here:
Transfer of services from Southeastern in 2018
7.17 We have yet to confirm the exact scope of services that we will transfer from Southeastern in 2018 and we are seeking respondents’ views as part of this consultation. Current thinking is that in addition to Thameslink core services serving Sevenoaks, these will be expanded to include Maidstone East. It is also possible that in peak hours this may include some services from Dartford and Orpington.
https://www.gov.uk/government/uploa...nt_data/file/2719/consultation-thameslink.pdf