In message , at 14:32:38 on Tue, 2 Jun 2015,
Mizter T remarked:

Abbey Wood is the end of the line. (Well, the Crossrail branch.)

Yes, so reversing the HEx2023 there will be easy.

Ok, leaving aside the fact that no such HEx service is going to exist.

It's a long time until 2023, nor do I see HAL dropping the brand
quietly.
--
Roland Perry