My take is that the resumption of that war in Iran makes it more likely that interest rates will rise, and rising rates means falling bonds prices.

yeah, as the article said bond prices have fallen slightly over the time period but this is much more bond buyers seeing increased risk SpaceX isn't going to have the cashflow or ease of further equity raises to pay them back in the long run. (With it being bonds the upside of "but what if SpaceX actually does become bigger than the present US economy" is capped too)