According to Apple's release notes, HomePod software version 16.2 adds performance and stability improvements, with no additional information. It's worth noting that alongside the new iOS and macOS updates, the HomePod software adds a new Home app architecture.
HomePod software is installed automatically on the HomePod unless the feature is disabled, but the HomePod can also be manually updated in the Home app by following the instructions in our HomePod update how to.
