there's no reason to leave everything in reserved for movies or TV shows that realistically are never going to use them. Star Wars was active from 1999 until the Disney sale and still had Books and Comics that weren't just the story of Padme Amidala's second cousins roommate. there is so many characters they just need to do something. even if it's just stuff to set up characters for later live action or animated appearances, they could definitely be doing a lot more. I would kill even just to see something with d-listers like Kyle katarn or dash rendar, two characters which have less of a chance of appearing on Star Wars tv or film than ET does. I could name a dozen characters that will absolutely never be used by the movies or shows but can make really good books or comics. It's not like a character appearing in a book or comic first precludes TV or movies from doing anything with them, anyway, and it would be nice to have more people involved in making creative works than just the story group and a few of their friends .
there's also the characters whose fate we know but have years of History open. We're not going to be seeing young Luke or Leia movies or shows, so some more books to be nice. Phasma is dead, so how about a book or comic that actually gives her full backstory unlike the stuff we got with her so far?
The comics get a bit of Freedom with this, certainly more than the books do. If we can get a comic series all about the cyborg Bounty Hunter from the ancient comic days, we can get books about something more important then shitty recreations of Romeo and Juliet or tales of Padme Amidala in between prequels.
As for Darth Bane, he'll almost certainly never be used again. Dave filoni only likes to use characters he created, and I'm wondering if we'll even get another Star Wars film in the next decade, and even if we do it's not going to be using Darth Bane. Its pathetic how much they're hoarding characters they know they never going to use. We're not talking about Ahsoka or rex or something like that, we're talking about the dozens if not hundreds of characters that existed before Disney bought Star Wars that could make for some great stories and have no reason to be shelved for shows or films they're never going to appear in any way