Not sure what was there before resignalling in the 90s or before. Will ask around. I think it's planned as an emergency turn back.
Well, I used to commute home from Ilford/Seven Kings eastwards in the early '70s. I distinctly remember the 306s pulling away and the trains not closing up to the up electric track until the train was doing about 45-50mph.
There were some sidings south of the main up which often had engineers' vehicles parked on them. The sidings originally served the Berger Paints factory there.
There was also a OHLE section break around there AFAIR (6.25kV ac), - maybe as that was there since the early '50s when the original 1500VDC was rigged, a decision was taken to leave the layout as it was, particularly as it was on the slow lines.
--- old post above --- --- new post below ---
Don't forget Ilford Platform 5 disappears with Crossrail so probably a bit more than an emergency turnback.
Presumably as platform 5 is too short for a 345 and no prospect of lengthening it as the flyover ramp is too near. They could terminate at Ilford by using the first two roads in the car sheds if necessary (or even Seven Kings and reversing into the car sheds' roads). Then there is Gidea Park, used for normal turning for decades.