As I read these forms, the only separation that would be reported would be his separation from active duty to the reserves at the end of his active service. His reserve records weren't requested. The term "all years" only applies to the records (active duty) that were requested.
Perhaps, but the section in question is entitled "SECTION I - INFORMATION NEEDED TO LOCATE RECORDS (Furnish as much as possible.)", so it may not apply to what records are being requested. If I was working at the records center, that's the way I'd interpret it.
However you have to also understand that one, at least officers, doesn't get a DD-214 when you leave Reserve service, but rather some other form, depending on circumstances. (My DD-214 was issued when I left active duty. I have a form from the OK ANG, but none from my reserve time, unless you count my orders transferring me to the retired reserve list or my retirement certificate issued at the same time, but that's because I never resigned my commission) Kerry's DD-214 was dated 1978, IIRC, years after he separated from active duty, leading to the supposition that it was a "deleted" DD-214, issued after the original was corrected during the Carter administration.