So they have about 1/3 of the money. I think we've seen this movie before.

If they just do the run-through tracks, and leave the fancy concourse for another phase, how much would it cost? The operational need is for the run-through; the current tunnel for platform access is funky but can still be used for a while.

As for passenger traffic, if the story is right and current traffic is around 100K/day, that's fairly impressive as rail stations go. It's a bit less than half of LAX. According to Wikipedia, LAX was the 4th busiest airport in the world in 2018, at 87,534,384 passengers (incoming+outgoing+passing through), which according to my trusty Windows calculator is an average of 239,820/day. 200K in 2040, of course, is in the ballpark of where LAX is today. It's also impressive in another way: none of the other LA area airports even make it into the top 40 (the Wikipedia list), which goes down to a bit less than 1/2 of LAX (around 40 million/year). Possibly adding a couple of them together (or even, maybe, all 4 of the others) would make it onto the list. So doing that with one stub-end rr station is pretty good under the circumstances.