Again, from the article; there is a defective wiring loom (from a supplier) this small number of cars were built using this loom. Once that loom is replaced, the cars should be fine.
The problem is not overly complex, but a bad decision was made to try to repair the looms on-site to keep the line moving.
Hindsight being 20/20, Challenger V6 production should have been halted until a new part was provided.
Chrysler, if knowing there was a potentially a long lead time, might have offered the owners of pre-sold and ordered cars a concession. They didn't and now, to their credit they are taking steps to correct the problem, albeit after the fact.
Without knowing all of the details, it sounds like the new quality procedures were not followed, at some point in the chain.
You can assume, it won't happen again, at least not in this manner.