The release list only keeps track of scene ROMs (i.e. numbered ones). If a game isn't in there, it just hasn't been dumped yet, or at least not according to scene rules. Doing a quick Google search tells me the PikaPika Nurse Monogatari ROM hasn't been dumped at all, so until someone dumps it, there will be no mention of it in the release list. I believe there are a couple of other games that have been out for ages and still haven't been dumped, though I can't think of any right now.

The upcoming releases list is based on the one on GameFAQS, so if a game isn't in there, blame them. The game was released August 4th, though, so it's no longer on the upcoming releases list.

Hopefully this solves your questions.