It's hard to find EMT that is not galvanized these days.
In my opinion worrying about contact between large galvanized and aluminum parts is generally worrying too much. In as much as it's an issue, it can generally be solved with stainless steel washers or similar small hardware. A stainless washer between
this style hanger and the aluminum is a pretty decent solution. If you're near the ocean, probably a good idea to paint the galvanized parts with some enamel to lengthen life, regardless.
My worry about the OPs picture is whether the EMT is held firmly by that hook. Not much point in having something that doesn't corrode if it doesn't hold the raceway tightly anyway.