The wiki says that Shadow Freddy appears in The Twisted Ones

The wiki says that Shadow Freddy appears in The Twisted Ones Novel. Is this true? If so can someone please explain the context? Is that why Nightmare appears on the cover?

Five Nights at Freddy's: Fourth Generation / Characters - TV Tropes

Nightmare, Wiki

The wiki says that Shadow Freddy appears in The Twisted Ones Novel. Is this true? If so can someone please explain the context? Is that why Nightmare appears on the cover?

Purple Freddy, Ultra Custom Night Wiki

Golden Freddy, Five Nights At Freddy's Wiki

So, basically now FNaF lore be like: : r/fivenightsatfreddys

Halloween Foxy

Shadow Freddy, The United Organization Toons Heroes Wiki

Freddy Fazbear (FNAF Books), Villains Wiki