Items Sets Bug

I may be wrong but Soul Anchor () is not available for Summoner's Rift Right? In that case, the Item Sets says

"This Item is not available on the following maps:

Howling Abyss The Twisted Treeline"

Again to my best knowledge i don't think it is available for Summoner's Rift. If it is then Soul Archer is not an item that people would take lightly for if they are not able to use it.