As someone who does have dual citizenship (UK and USA) and has been a BOA customer for over 20 years, my big question is what happens if you say "yes"? I didn't see this mentioned or discussed yet in the comments so far.
Think of this as NSA meta data gathering. NSA doesn't search metadata every day for some body. Instead, they use the meta data once suspicious person is located by other means.
IRS, FINCEN, FBI, etc want to have access this info on their fingertips.