TLDR: When George Lucas sold the Star Wars rights he kept some percentage of the royalties for the merchandise based on the old trillogies. Disney doesn't get anything from selling Solo, Leia or Luke figurines/stuff. But anything new they create belong to them and they get the merchandise money. So they literally destroyed the old characters to lower the interest for them and boost the sells based on the new characters. For context if you think they wouldn't do that to your favorite movie for money: SW merchandise alone (excluding movie revenue etc) generates 1,5 billion dollar per year. Yeah, they would.