The problem is that Google infra requires everything running to be new. There is a build horizon of 6 months. Everything built with code older than 6 months is not able to run on Borg. And since Google deprecates many internal infra tools/libraries routinely, a team is required to make sure the service remains up-to-date. Google doesn't want to pay for such maintenance.

This what I'd suspected as pressure to discontinue services that could otherwise virtually maintenance-free at low cost.

In S3, you can implement this with a single bucket, no code at all: objects can cause redirects, using x-amz-website-redirect-location

Since Google buckets don't seem to implement this feature, maybe they should point goo.gl at S3 :-)

Oh cool, I've done this sort of thing (mass redirects) with Lambda@Edge which allows for more flexibility, but probably costs more.