Yes, that's true. If the person with the pickup had not blocked the tracks, there would have been no wreck.

However, the "pilot" at the cab end of a cab car is supposed to be strong enough to dislodge and push aside a light vehicle without allowing junk under the train. A pickup truck is definitely a "light" vehicle compared to a cab car, and many have been hit under various circumstance by cab cars with little damage to the train. So if there's clear evidence of a pilot failure allowing debris (which the pickup truck was after being hit, as well as the pilot pieces if it collapsed or broke apart) to get under and derail the train, which it sounds like, we have something that can be fixed. Apparently, a fix is also proposed, though NTSB et al would probably want a little more information that a news article/press release provides about how the fix is engineered and tested.

Note that you can't always prevent something bad from happening. Murphy Lives. You protect against everything you can think of within a reasonable budget, but in a way you're always fighting the last war. An old line applies: just when you think you've got it foolproof, along comes a better Fool.

Relevant since Amtrak runs on the same line: would a Cabbage have performed any better in that type of wreck?