There is no potential release yet for v7, and we are generally waiting for the surrounding ecosystem and supporting projects to catch up to JDK 21 and all that it requires; a best half-educated guesstimate is very late 2023, or early 2024 Q1. You may prepare beforehand and start experimenting with the regular cadence of RCs.
The typical plan is for the project to manage 3 active release lines; until v7 is released the other two release lines will be maintained per maintenance policy, and their SPM/EOL dates would be fairly stretched out until shortly after the v7 release.