LXD 5.16 will remain in the latest/candidate channel and will not be pushed to latest/stable.
The latest/stable channel will jump straight to LXD 5.17 when that is released.
This is because during testing of latest/candidate some minor issues were identified and fixed, however the build of LXD on arm64 in that channel was delayed due to unrelated changes happening in Launchpad (which builds the snaps for LXD) occurring at the time.
We did not want to push the architectures that had built correctly to latest/stable to avoid causing problems with users running mixed architecture clusters that included arm64.
These changes in Launchpad have now been rolled back and the latest/candidate channel now contains the latest LXD 5.16 build (including cherry-picks) for all architectures.
However to be safe we will not be promoting 5.16 to latest/stable until we are confident that we can quickly deploy any cherry-pick builds required for all architectures.
We continue to work with the Launchpad team to resolve the issue.