Unfortunately, even with the regulations that have been in place, the immigration officials can exert their own prejudices.

Whatever the published policies are or have been, if an official wants to deny you entry, they can do so - no matter what the terms of the temporary shore leave visa. This rarely happens to North Americans and West Europeans, but does happen to those from other regions (especially other parts of Asia). Unfortunately, although I would like to assume that this is a rare occurrence, I honestly don't know how common this is, or the extent of the problem. Most of those affected are not English speakers and wouldn't post their experiences on a website like this.

I'd also suggest you contact the Japanese Embassy/Consulate in your country and make a polite enquiry about whether the terms and requirement for shore leave privileges will be changing - an email should do it.

Do please report back. Your own visa requirements are quite different from those of most of us who post here - but this makes it all the more important that your experiences are reflected and shared on this forum.