This applies to all the Bakken producers. Suppose this happens: The current unmodified railcars that are transporting 70% of the ND oil are not permitted to do it until they are modified for safety reasons. There would be a temporary backup of 0il leaving ND and a loss of income for the producers.
This would never happen. Shutting down 70% of ND would immediately spike oil prices 10%. That in turn could cause a ripple effect in the economy and re-ignite fears of a recession.
A more realistic scenario would be to provide dates with milestones that pertain to safety with the rails. Nobody is shutting down the Bakken unless there was an epic proportion type catastrophic event.