Thanks for the link, so in other words work is carrying on as it was before, but still at a slower pace than everybody would like. Based on the comments in that article, I'd expect roughly the below timescale:
Phase 5a (PAD-RDG): December 2019 (7-car), May-August 2020 (9-car)
Phase 2b (PAD-Heathrow): May 2020
Phase 3 (ABX-PAD): May-September 2021
Phase 4 (SNF-PAD): December 2021 or May 2022 (7-car LST-GDP)
Phase 5b (RDG-ABX): May or December 2022
LST platform remodel: August 2022, 9-car LST-GDP services to follow Oct-Dec 2022
Overall, broadly 3 years behind schedule. May-Sep 2021 for the core is pessimistic based on those discussions but I think reasonable in the context of how that continues to slip day by day.