Similar how we do chaos testing, I want a Bigtable instance (or a cluster) to be down. Like it goes down in any outage/catastrophic event.
It is not possible to take down a Bigtbale instance without deleting, unfortunately. You could use Backups for your testing:
Bigtable backups let you save a copy of a table's schema and data, then restore from the backup to a new table at a later time.
There is also a Bigtable emulator which can be used for application testing.
I'd also like to encourage your to create a Feature request for Google to consider this feature.