I refer you to the thread on
Northern's timetable plan for May 2018.
The Calder Valley service is to start in May 2018 - it was always due to run on Sundays from the first timetable change, so it is unclear whether this is a change or an omission from the specs.
Similarly the 2tph from Bolton to Stockport appear to start in May 2018, with the following departures from Piccadilly.
So AFAIK from May 2018, the plan appears to be 12tph (+freight) through the platforms, with no further services in 2019:
TPE 3 (1 Scotland and 2 Leeds)
Northern EMUs 4 (2 Blackpool North, Chat Moss, Wigan NW(Flex?))
Northern DMU 3 (CLC, Cumbria, Calder Valley)
EMT 1
ATW 1
Yes, Northern would have liked to run a Todmorden Curve - Airport service and the residents of Southport would like to retain a Piccadilly service, but these aren't commitments.