Weird that this is US first when in the UK it’s extremely rare not to be able to use contactless. (I only say UK as I live there, but definitely there are other countries that are heavily focused on contactless)
Apple might perceive a large advantage to moving quickly in the US market right now, that there is something to gain by grabbing land there sooner rather than later (as opposed to rolling it out in various smaller markets with higher % contactless rates first).