Explanation
Since they have already paid for data center for another year. They have the time and resources to work with, They can make the change to their workloads locally/on-promise Improve and Migrate Move to Google Cloud later on.

https://cloud.google.com/docs/security/encryption/default-encryption#:~:text=Google%20uses%20the%20Advanced%20Encryption,to%202015%20that%20use%20AES128

The above is a real world example of a company named Planet, where they sent around 80+ satellites to take pictures of earth every day, 24 hours. They run around 40,000 preemptible VMs concurrently.
Preemptible instances function like normal instances but have the following limitations:
Compute Engine might stop preemptible instances at any time due to system events. The probability that Compute Engine will stop a preemptible instance for a system event is generally low, but might vary from day to day and from zone to zone depending on current conditions.
Compute Engine always stops preemptible instances after they run for 24 hours. Certain actions reset this 24-hour counter.
Preemptible instances are finite Compute Engine resources, so they might not always be available.
Preemptible instances can't live migrate to a regular VM instance, or be set to automatically restart when there is a maintenance event.
Due to the above limitations, preemptible instances are not covered by any Service Level Agreement (and, for clarity, are excluded from the Compute Engine SLA).
The Google Cloud Free Tier credits for Compute Engine do not apply to preemptible instances.

Reference link- https://cloud.google.com/compute/docs/instances/preemptible

Explanation
In cloud computing, multitenancy means that multiple customers of a cloud vendor are using the same computing resources. Even though they share resources, cloud customers aren't aware of each other, and their data is kept totally separate. Mul-titenancy is a crucial component of cloud computing; without it, cloud services would be far less practical. Multitenant architecture is a feature in many types of public cloud com-puting, including IaaS, PaaS, SaaS, containers, and serverless computing.

Compute Engine provides machine type recommendations to help you optimize the resource utilization of your virtual machine (VM) instances. These recommendations are generated automatically based on system metrics gathered by the Cloud Monitoring service over the previous 8 days. Use these recommendations to resize your instance's machine type to use the instance's resources more efficiently. This feature is also known as rightsizing recommendations Reference link- https://cloud.google.com/compute/docs/instances/apply-machine-type-recommendations-for-instances