We're straying a bit off topic here, although Piccadilly platforms 15/16 were at the heart of the Manchester Hub project (that morphed into the Northern Hub) that included the Hope Valley Scheme and that controversial chord - that would all have worked a lot better if all were done in full.
Delays are nothing new, the Dore station redoubling was originally scheduled by Railtrack for 2003-4. Re-signalling of the entire Hope Valley route has been on the cards since 1988 but west from Earle's Sidings remains to be done, no longer a priority it seems. Electrification is unlikely before operations cease at the Hope Valley cement works about 2042 so one complication removed. Electrification from Dore into Sheffield is supposed to happen by 2030, so said Grant Shapps in December 2021 when speaking to the Sheffield Star;
Grant Shapps MP said he was ‘aware of the history’ but insisted he ‘absolutely, fully’ intends to complete electrification of the Midland Main Line to the city by 2030.
A lot of work has gone into HS2 creating masses of paperwork and computer files to trawl through. I'm looking at the October 2018 Working Draft Environmental Statement Volume 2 for the Unstone Green to Sheffield Station section. Most, probably all, of that work will be needed for MML electrification. Para 2.2.3 Allows for a 1 km overrun at Dore junction, effectively through Dore & Totley station. (Power supply near Chesterfield in the Danesmoor to Brierley Bridge area and switching station at Dore.) Timescale envisaged - between 2023 and 2033. I'd now estimate an earliest date of nearer 2035 for the current MML bit, including Dore & Totley station.