And Trump thanked them!

He did explain the reason. Garden hose.

I’m sure Google does monetize the gps data instantly, then throws it away rather than save old data that only costs money to respond to government requests.

This is a case where privacy is economically beneficial to Google.

The device only was for privacy. When the data was stored in the cloud, the government had unrestricted access. By making it device only they need to get your device to get that data.