Well, they kindasorta fixed the Fatal Frame tag on AO3....

So, sometime last year they merged the first Fatal Frame game into its series tag.

Looks like they kind of fixed it and it now lives on as "零～zero～ | Fatal Frame (Video Game 2001)". I'm really not happy with their choice but I guess it works?

Worse, you have to manually update to the new tag, which I think is stupid, but I now have all my Fatal Frame I stories in the new updated tag.