I wonder if Maul will play into the Kenobi spinoff in that Obi-Wan leaves to confront Maul and ends up taking down Crimson Dawn and leaving Maul stranded on Malachor with a live action replay of their final duel for a coda.
If they don’t make a Solo sequel, I think it would make more sense to put Maul, Qi-Ra and Crimson Dawn into the upcoming Boba Fett film. Even Ehrenreich might be in it. I hardly doubt that they have any specific plans for the plot of the Boba Fett film, but they could easily put Crimson Dawn into that movie. That could also give the more casual fans a “proper” explanation as to how Maul is still alive. (It’s also not impossible that the Qi-Ra/Solo sub-plot might be resolved there.)