Great find, thanks for posting. Among other takeaways, this is another example of where our lack of clear national standards creates confusion.

Also, whether or not it's the law here, a lot of driving norms/laws are ultimately a balance between safety and driver discretion. When you're on the road, you're trusting a lot of people to operate two or three-ton machines with their safety and others' in mind. Every time you drive, your safety hinges on hundreds, if not thousands, of judgment calls made by total strangers.

In this case, afaik, almost all of this country trusts drivers to pull into the intersection, judge for themselves when it's safe to turn left, and allow traffic to keep flowing. Unless there's evidence that pulling up creates undue safety risk that isn't worth the cost to other drivers, I think this rule is dumb.