Kali Linux 2020.3 is a distribution built for security professionals and comes with software packages and tools that can be used by ethical hackers to perform penetration testing. With this release, the Kali Linux Team begins their plan to switch from a default Bash shell to ZSH. ZSH will also be installed with a new configuration created by the Kali team. Every tool in the Kali menu will now sport new themed icons, which are displayed below. The Kali NetHunter mobile penetration testing suite has been updated to include the new Bluetooth Arsenal tool to discover bluetooth devices and snoop.
Source: https://www.bleepingcomputer.com/news/linux/kali-linux-20203-begins-journey-of-replacing-bash-with-zsh/