Yes, that's what it seems like. Arizona and other states had used lethal gas as a capital punishment for decades, and it's only now that someone brings this up? Arizona stopped using lethal gas and switched to lethal injection, although state law permits inmates who committed their crimes prior to 1992 to opt for lethal gas. There are only two people on death row to whom that would apply, and it's because of that that Arizona was getting the old gas chamber ready for that purpose. All of this had been reported back in April, and it wasn't really any great secret.
The story in this thread focuses on the actual chemicals they purchased to make the gas. I don't know the chemical composition of Zyklon-B or how it compares with gases used for executions in the U.S. I'm also not aware that the law requires any specific chemicals to be used or not used; my impression is that such matters would be left to the discretion of the DOC, who would likely just go along with whatever works.
Beyond that, I'm not sure what the significance is. If they're trying to suggest that Arizona Republicans are a bunch of Nazis, then that may be an example of yellow journalism. I'll admit we do have a reputation for right-wing politics, but that's been slowly changing.