A go/no-go decision is an explicit, binary determination — go, or no-go — of whether something is ready to proceed, borrowed from aerospace and operations contexts where ambiguity in a launch decision isn’t acceptable.
Applied to a marketing launch, a go/no-go decision replaces a judgment call ("this seems mostly ready") with a clear, checkable status: every required condition either has been met, or it hasn’t. This matters most when a launch involves several people and systems, because it removes the ambiguity that lets a partially-ready campaign ship anyway.