Billy Dee was available (and willing) for VII, JJ just didn't care enough about Lando to add him in.
Rian thought of Lando, but he "Had to be" DJ, and that wouldn't fit Lando, so Lando had to go (re-write you HACK!)
It's pretty clear if Carrie Fisher was still around JJ wouldn't have called Billy Dee for IX, passing him before. He's just there to replace the carrot that passed away. Talk about insulting. For that reason alone no-one should watch IX. They have their mouth full with "diversity" and other nonsense, but they overlook Lando Calrissian and our interest and fandom of him ENTIRELY only bothering to add him once all others fall away. Again, it's insulting of the highest degree, and they expect us to praise them for it. No, no way in hell.