An LJ reader sent me this letter from his insurance company regarding the new immigration guideline which appears to confirm that the stance on the guideline has been softened. As the letter points out, not being enrolled in a public health plan is insufficient grounds for declining a visa renewal application. It looks like a lot of instructors can breathe a sigh of relief.
Update 11/28: Hoofin makes some salient points on this issue. The focus on Guideline 8 is misplaced in that it doesn't supersede the fact that the law still compels you or your employer to enroll in a national health plan while you are working in Japan. Instead of faxes from Diet members and comments from the Immigration Bureau, we should be seeking answers from the Health Ministry and Social Insurance Agency who have authority over this matter.
Update 12/7: Dmca.com has contacted Let's Japan and informed me that their client requested that this URL be taken down since I posted private and confidential correspondence intended for their client only. On that note, I've removed the letter from this post.