There’s no way spanner gets shut down. It’s critical to so much of Google’s internal infra.
I think the "google shuts things down" trope is justified and something that I wince at every time I see something like this, but GCP isn't a random pet project that loses money and has no users. It's a very successful enterprise business.
(disclaimer: I work at google in cloud, so obviously I have personal bias, but this is just my opinion based on the pure numbers.)