I haven't heard that before.
There was a major case of theft from Japanese ATMs a couple of years ago. That prompted Japanese banks to make some changes to protect themselves. (The most noticeable change from the foreign tourist's point of view is that the daily withdrawal limit was lowered). Perhaps they also changed some terms and conditions to reduce their exposure to risk - and your credit union won't accept that? That's the best theory that I can think of. Perhaps some of the experts here will know the real reason:
https://boingboing.net/2016/05/23/co...-in-japan.html