When does a measurement ID change?

[IchordeDionysos]

When looking at the domains that are used by the Firebase products for B2B customers, I stumbled upon this request to firebase.googleapis.com/v1beta1/projects/-/webApps/-/config endpoint.

Looking into the source code it seems like it's used to fetch an up-to-date version of the measurementId.

Why does the measurement id change, resulting in the need to re-fetch it every time?

Just want to understand the reasoning behind that as it feels a bit odd that the ID would change and have to be re-fetched every time.