Maz Kanata was kind of the Yoda character in The Force Awakens. While she wasn’t a Jedi, she was Force-sensitive and was able to give Rey guidance in the ways of the light side. She was a unique little orange alien with sunken eye sockets that got big once she put her goggles on. These goggles let her look into people’s eyes to see what their true feelings and intentions were.
Kanata was also over 1,000 years old and owned a bar that was open to both allies of the First Order and the Resistance. Her castle was a neutral place that any smuggler or mercenary could take refuge in.
Kanata was old friends with Han and Chewie and was very open with her feelings for that Wookiee. Maz also had Luke’s lightsaber in a trunk, and it was never explained why. That is something that The Rise of Skywalker could address. It wouldn’t need to be a long explanation but just something to tie up that loose thread.
Even if that doesn’t get explained, seeing Maz Kanata back in the flesh in Episode IX would be great. She could offer help to the Resistance in the form of ships and connections, and with her Force abilities could prove to be a valuable fighter if she were to take part in the battle.