Been writing my release scripts like this for years. Like you I didnt know there was a specific term for it.

As one co-worker said: "write it like this [ed: idemptent] then no one will notice if you release a script half asleep or whether you got distracted, you just run it again".

When Fire fighting an issue and the pointy-haired-boss starts asking damn fool questions an idempotent script does reduce a lot of risks.