I'd be very disappointed if you went to all the trouble of building stations, 4-tracking to provide extra capacity, and then didn't put in some extra services to take advantage of the new capacity. I'd go as far as to say it wouldn't be worth doing if you weren't going to provide some additional trains. As noted upthread, I'd hope you'd see something like a half-hourly Morecambe-Lancaster-Preston-somewhere replacing the existing Morecambe service to serve all the new stations. And maybe also have the somewhat irregular Northern Barrow/Windermere trains also call at Bailrigg.
Then we’re into building new platforms at Preston…