The reason why KOTOR 3 hasn't been greenlit is pretty simple, IMO. EA has no interest in that style game anymore. They don't want a purely single player game with a heavy story focus. They just don't. At least not ones they'd have to spend a fortune on.
They want something that can be turned around quick while leveraging popular IP, and I think EA will probably double down on that after Anthems rocky launch. EA is more likely to sell microtransactions garbage in an online multiplayer title than a single player story based title.
Bioware has never shipped a game that sold enough units to justify the budget that a AAA "KOTOR 3" would demand with Disney's royalty. Beyond that, what is "KOTOR 3" in 2019 when Disney is not interested in letting a licensee continue that story line? If I was a VP at EA and a Bioware executive producer pitched me on DA4 and "star wars RPG project" I would greenlight Dragon Age every time, confident in the knowledge that the studio was capable of delivering a high quality and maybe, eventually, profitable game.