I ended up moving them, expecting it to be a non-controversial change as Shadow Crystal Boss recently got moved to pluralize the title (For consistency with other gameplay mechanics such as Great Doors, Titans, Dark Fountains, etc), but it got reverted.
No. And I don't think Shadow Crystal Boss should be pluralized either. It’s been under a singular title for a while, I don’t see a reason to move it to plural.
I definitely think that the titles should be singular. They would be easier to link to, and we wouldn't have to needlessly link to redirects. This applies to all pages with plural titles such as Great Doors and Dark Fountains as well.
The problem is that is inconsistent with some other mechanic articles.
Personally, I would think moving the plural titles (Great Doors, Dark Fountains, etc) to be singular is the better choice; it's just that moving these two only, would be less moves (Which is why I did it when moving it myself, but now that we're discussing it, this may be the better choice).
The truth is that there was no consistency in casing before, and there is no consistency in casing now. The articles were named by however the article creator decided to name them, and then just stayed like that. There is no standard on this, and I very much do not appreciate when editors single-handledly decide on a standard, then start applying that standard across all pages on the wiki to match even though it was never agreed upon.
There is a lot of articles to take into consideration here, not just gameplay mechanics or plot elements. If you can wait for a bit, I would rather we start a community vote on this later, especially with upcoming major updates to the standard.