By closing they mean small IRanian boats threatening large vessels including the one billion dollar US navy ship,... not actual closure, correct???
Not likely. iran's military strategy is not to fight symmetrically.
The More likely approach is iran's puts in a few sea mines in the Strait.
Calls it all ships. all insurance companies tell ship companies well don't move your ships into or out of strait.
then the u.s navy gets in to try to swipe them up.
Iran sends in the small boats to harass the big ships and mostly try to slow them.
if U.S navy escalates the situation by shooting a whole of bunch of the boats down, iran might choose to escalate the situation. by trying to make the water for u.s vessels more unsafe by shooting land to sea missiles.
if any of the U.S navy ships get hit then U.S navy will start a long bombing campaign to take all of iran's missile sites, artillery battery sites.
at the very least the southern airports.
then iran has to decide if they want to escalate the situation further.
this is what they call
"war games"