Root Cause Assessment
[tjpa.org]
If you translate this into plain english, this was a design error. That bodes well for re-opening.

In other news, the designers have "refined" the alignment of the Downtown Extension (DTX) and added new permanently crippling features:
1) on the Townsend portion of the alignment, the speed limit was reduced from 40 mph to 35 mph, with a couple of new kinks that are limited to just 30 mph
2) the Townsend station platforms will be just 700 feet long, precluding Caltrain from docking longer trains than 8 cars at this important stop.

Reminder: to reduce travel times, you need to speed up the slow bits, where the marginal cost of each second saved is lowest. What they are doing here is exactly the opposite, delaying the slow bits and adding seconds of delay to millions of future trips that will be more expensive to recover in other faster portions of the system.

On the plus side, they shortened the throat interlocking by 500 feet, although there is still room to tighten it up by at least another 300 feet. Shorter interlocking plants have higher route availability and throughput.