I truly do not think Trump had no plan about the closing of the Strait of Hormuz. He knew Iran would shut it down, and I believe his inaction there was deliberate.
Trump is not a genius (quite the opposite), but he is strategic, and he is revenge-driven.
The US could’ve easily kept the Strait of Hormuz open by enough prep in advance. Not doing so was a choice. A poor choice, a misguided one, but a choice nonetheless. And the point of that choice was making our allies look bad, embararasing them, and inflicting pain on the rest of the world for their lack of support (or for being rivals, like China) for our actions in Iran.
Remember, the US is energy self-sufficient now1 and we cannot even refine the oil that comes out of Iran. Our oil infra is not set up for it at all.
Though I do not believe attacking Iran as we did was the best choice, I don’t care even a little what happens to the mullahs there, and they were likely getting pretty close to having a working nuclear weapon (unlike Iraq back in 2003). This would’ve been bad for everyone, but far more so for the rest of the Middle East and Europe.
Thus, the closing of the Strait was Trump’s revenge on those who did nothing to assist in an action that directly benefited them — i.e., significantly degrading Iran’s nuclear ambitions.
The rest is just noise.