The genus Mycena is "imperiled" in British Columbia?

I’ve always thought of the genus Mycena as a large, common, and very diverse group of agaric fungi, especially here on the Pacific coast of America and Canada. So, since when has the genus been “imperiled/vulnerable”? Is this an error? I tried searching the website that was cited:

Conservation Status: imperiled (S2S4) in British Columbia, CA (NatureServe)

and I found nothing…

How could this be? If this is really true, what does that mean for the species? A few miles to the south in Washington, there is no vulnurable status on observations of Mycena.

Sorry for dragging loloxd into this, if you’re reading this.