Many cards that do exist in Hunterer should have received the errata, but do not show up in a search for Phyrexians.
Inexplicably, Sheoldred, Whispering Onedoes show up in the search for Phyrexians, but her own card page does not report the Phyrexian type. I don't know what's going on there.
The Kaldehim Oracle update introduced a sweeping set of errata, updating many past cards to be Phyrexian. Currently, the game has about 265 Phyrexian cards.
Hunterer only has 60. This appears to be a subset of cards released since Kaldheim.
Many cards that do exist in Hunterer should have received the errata, but do not show up in a search for Phyrexians.
Inexplicably, Sheoldred, Whispering One does show up in the search for Phyrexians, but her own card page does not report the Phyrexian type. I don't know what's going on there.