Personally I assume there was an implied /s at the end
Well, there's an unspoken rule in SV/HN circles about when the take Trump's idiocies seriously and when to ignore them.
For example, "Gulf of America" and "Department of War" you're supposed to take seriously, and all SV communications feature these prominently. Correcting someone about the fact that "The Department of War" doesn't exist will get you downvoted, but apparently you're not supposed to take "Straight of Hormuz is US territory" seriously? I'm am very bad at discerning this rule.
I can imagine Pete Hegseth saying that exact sentence to President Trump.