It's actually somewhat comical I haven't seen a single article suggest this as I would think this would be everyone's first choice.
Everyone seemed to really connect with the character Baylan and Ray Stevenson was beloved by fans. So as to the question of what to do with the character going forward? My answer is this.
Why wouldn't they just give the character a mask?
Star Wars is a series pretty driven by people wearing masks and us not knowing who they are.
This seems like a obvious solution to the problem. Respectful to Ray Stevenson (Who I don't think anyone is arguing did a brilliant job with the character.) in both not recasting and continuing his character's story arc on for years to come.
This has been done in this IP in the past with Darth Vader who was not played by the person who voiced him and neither of the actors were who was revealed to be under the mask.
You could even look at the Clone Wars which had major characters being voiced by different actors, yet continued to use the original actors likeness. Which we saw again in Tales of the Jedi. Both Dave Filoni projects so the man has experience casting for this situation.
I don't know what Dave Filoni has planned, but I hope he has at least considered this idea. I hope I'm not the only one who's thought of this because maybe that means Dave has had the same thought. I guess we'll find out and hopefully its sooner than later.
But of course we all know the stipulation is the best part of this stuff.
Set after the fall of the Empire, Ahsoka follows the former Jedi Knight Ahsoka Tano as she investigates an emerging threat to a vulnerable galaxy.
In addition to Rosario Dawson in the title role, the series stars Natasha Liu Bordizzo as Sabine Wren, Mary Elizabeth Winstead as Hera Syndulla, the late Ray Stevenson as Baylan Skoll, Ivanna Sakhno as Shin Hati, Diana Lee Inosanto as Morgan Elsbeth, David Tennant as Huyang, Lars Mikkelsen as Grand Admiral Thrawn, and Eman Esfandi appearing as Ezra Bridger.
Ahsoka was written by Dave Filoni, who executive produces alongside Jon Favreau, Kathleen Kennedy, Colin Wilson, and Carrie Beck.
Directors include Filoni, Steph Green, Peter Ramsey, Jennifer Getzinger, Geeta Vasant Patel, and Rick Famuyiwa.
All episodes of Ahsoka are now streaming on Disney+.