I think it's one of the best ideas he's had. The US has done nothing to disrupt any of the shipping through the strait throughout the war. They've let all the Iranian tankers and bulkers through, which effectively allowed Iran to cash in on high oil prices while they disrupt the rest of the world economy. Then the ceasefire was allowed to continue for days even though Iran failed to live up to the only precondition of opening the strait. The US now has credibility that the issue of the strait closure is Iran's fault even though the US might add to the pressure with a blockade.
I think it's a long time coming. Iran has been able to feel very powerful by choking off the rest of the world without affecting themselves, so they felt no need to cede anything in the ceasefire demands. At least this would add some pressure to them, turning it from a cash cow to a pain point.