Random Event Antag Prompt should tell you what Antag it is

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I'd recommend trying it and if metagaming becomes a problem then doing something about it. In my experience folks who happen to die and get revived in nuke before the nukies are revealed generally don't tell anyone, so the player base is probably decent enough to keep this quiet.

It might mean that we never see a random event blob on Atlas again, but that's not really a downside.