Well first of all, I don't get how a single oil tanker being hit could shut down a shipping lane that's two miles wide. Additionally, Iran has threatened several times to shut down the Strait but never has, you know why? Because almost all of their exports need to travel through it. Also, China is the biggest buyer of oil traveling through the Strait so there's no way they're going to let it get shut down.
If you haven't noticed, Iran loves talking trash and not following it up. They're not shutting down anything.