I think casino owners are not dumb enough to remove their source of advantage.  I think they can lower their house edge but will never remove it.  As far as I know, the highest RTP available in the slot game is Ugga Bugga (Playtech) @ 99.07%.

So I believe it will be impossible to see a game with 0 house edge, if there is one claim about having a 0 house edge, it is misleading or it might be a promotional offer by a casino in a limited time.