And if there's no new line? You don't completely shift a city centre station away in the hope that one day it'll have a new alignment to justify it. I've said this before and I'll say it again, if HS2 struggles to reach the north of England, there is zero chance of a new alignment across the Pennines.
Lets be honest, any new alignment that is predominantly tunnel from Huddersfield to Bradford is going to have some quite spectacular issues in construction due to the phenomenal amount of legacy coal mining there.
It would not be cheap. And would likely be the first thing on any budgetary chopping block.
The intricate design required for any new station regarding routes, track alignment would make it folly to construct anything major in advance of this mythical new route.
Look around the country at all the bodged bits of motorways that were connected together or where we have massive junctions because there was an airy scheme about future works that were so far up the magic money tree.
Bradford doesnt need the promise of something shiny in the 2040s, it needs something much sooner or it will continue to fall behind Leeds to the point where in 15 years it may just be a satellite town to Leeds.
I have lived in Leeds since 2008 and have seen just how much building has gone on in the last 5 to 10 years alone. You see the commuter flows in the morning and Bradford is a long way behind.
The money you would spend on this station and alignment would massively outweigh the cost for electrification of the calder valley line and some enhancements at interchange with real money left over for regeneration of Bradford, not leaving it with idle hope in regeneration around a new station in an industrial estate.
You can then regenerate an area that is suitable. Kirkstall forge as an example should by now be a huge metropolis around a station with services direct to Bradford and Leeds. But i believe its developer went bust, the majority of thr site stands empty with one unfinished house, yet less than 3 miles away huge numbers of buildings are going up in Leeds city centre.
Bradford needs real investment today. Not the promise of riches in 20 years time.