Currently, extension authors get their pre-release versions tested by the community using VSIXs. But VS Code does not support installing alpha/beta/insiders versions. This force authors to always use patch for pre-release versions.

By supporting alpha/beta/insiders versions, author can generate VSIXs like pub.extname-0.11.0-beta or pub.extname-0.11.0-beta-2. At the end, they can publish the release version pub.extname-0.11.0 and all users who are using pre-release versions will get the release update.