IMO “dude” as an interjectory term of direct address is fairly gender neutral (as in, “Dude, not cool!”), but if someone says “that dude” I assume they’re referring to a man; in fact, the first time I wrote this sentence I naturally wrote, “I assume they’re referring to a dude”! It’s similar to how “man” can be as an interjection (“Man, I could really use a drink”), although in that case “man” often lacks an actual referent whereas “dude” typically has one. The interjection bit is key–“Sup, dude?” is heavily masculine-coded to me, although perhaps not as exclusive as “that dude.”

That’s all to say that if you referred to an audience as “dudes” I would assume they’re all men. On the other hand, “you(se) guys” to me is fully neutral and I hear groups of women refer to each other that way all the time, although I try my best to use more explicitly inclusive language when addressing people whose preferences I’m not sure of. Language is fun!