Apple's Magic Keyboard, Magic Mouse and Magic Trackpad will eventually switch from Lightning to USB-C in the spring of 2024. It's unclear if there will be any other changes to these accessories besides the switch to USB-C. They look largely the same as when they were last majorly updated in October 2015, though there have been some minor changes over the years, including a switch to braided cables and new color options that are only available on the 24-inch iMac. In 2021, Apple also released Magic Keyboard with TouchID button.
While the MagicMouse lasts about a month or more between charges, the placement of the Lightning port on the bottom of the accessory has been the subject of ridicule for years because it made it impossible to use while charging. It's unclear whether the new version's USB-C port will be placed in a more convenient location.
Ever since Apple began its transition from Lightning to USB-C, changes to its peripheral ports have been widely anticipated. Despite rumors that Apple would change the ports when it releases the new iMac in October, no such change has occurred, with all three accessories still using Lightning ports for charging and syncing.
Apple's decision to keep the accessory unchanged is notable as the company has gradually moved toward USB-C. The entire iPhone 15 series, all latest-generation iPad models, Apple TV’s Siri Remote, second-generation AirPods Pro and the new Apple Pencil now use USB-C ports. In addition to the three peripherals matched with iMac, only AirPods, AirPodsMax and iPhone SE among the latest generation of Apple devices still use the Lightning interface.
Given that the iMac was just updated five to seven months ago, it would be unusual, but not impossible, for the various "Magic" Mac accessories to be updated at this time. Apple is rumored to be planning to release multiple products in the spring, including new iPads and Macs, as well as the Vision Pro headset.