Big thanks goes out to jessejlt for pointing out this update by Slashdot:
The post to Politech says the songs would "disappear," not be deleted; from the context, it seems they were merely unplayable, not deleted. Apple has contacted the guy, and is apparently making him happy. However, the question remains: Apple definitely doesn't want people buying new songs from outside the U.S., but do they intend to generally permit foreign users to reauthorize (in effect, retain access to) the songs they have already purchased? Apple's policy is very unclear on that point.
News source: Slashdot