1. Local PC
Basically, they can be used until just before the latest version is released. This makes it possible to have a beta version of Chrome on hand for testing before release. See here for how to test using beta versions.
2. Cloud browser
These are supported for approximately two weeks after Chrome is released, but sometimes there will be an issue on the Chrome side and it is not possible to upgrade. In such cases, a specific version may be skipped, and the update will occur when the next version of Chrome is released.
Please refer to releases to check the status.