IDK where you got that Sowerby Bridge will be a Northern Connect station no Northern connect services are planned to run from there and neither will they stop at Mytholmroyd , Hebbden Bridge, Accrington and Poulton le Fylde (the last ones not really as relevant)
also the Blackpool to York Northern Connect service will only stop at Leeds, Bradford Interchange, Halifax, Burnley (According to the Northern Connect page but I can't seem to find anything about that on wikipedia), Blackburn, Preston & Blackpool North.
(SOURCE:
https://www.northernrailway.co.uk/travel/northern-connect)
And since i've found that via Wikipedia and Northern's website i've come to the conclusion that the service Leeds to Blackpool North will likely terminate at Preston again when the Northern Connect starts but until then I guess time will to see what stops it will stop at.