On Fri, 26 Jun 2020 08:04:23 -0000 (UTC), Anna Noyd-Dryver
wrote:

AFAIK the shared sections will retain lineside signalling (similar
arrangement to the Central line with an additional aspect for ATO trains,
though in this case I believe it will be blue rather than white); but the
resignalling of Harrow and north thereof is currently on hold.

I would expect trainstops to be retained, or possibly TPWS to be fitted
instead.

Speak to TC. Big changes are afoot and lots has now been abandoned!