As new versions of the Microsoft Graph REST APIs and Microsoft Graph SDKs are released, earlier versions will be retired. Microsoft will declare a version as deprecated at least 24 months in advance of retiring an API or an SDK. So Microsoft Graph too follows the Microsoft Lifecycle Policy.
When we increment the major version of the API (for example, from v1.0 to v2.0), we are announcing that the current version (in this example, v1.0) is immediately deprecated and we will no longer support it 24 months after the announcement. When an API is marked as deprecated, we strongly recommend that you migrate to the latest version as soon as possible to avoid being affected.
For more info you can refer our support policy documentation on the same.
Hope this helps.