I really think the ability to do anything in the space of episode 7+ got completely handcuffed the minute the Zahn trilogy came out in the '90s and was insanely popular. Any movies made after that point would've had to either just be adaptations of existing EU material or figure out a way to play nicely with it, which doesn't strike me as something Lucas ever would have been particularly keen on doing. Which is to say, yeah... Lucas should've really just started making more movies around 1990 if he actually believed in his trilogy of trilogies spiel.
Disney's alienating choice to pitch out the majority of the EU was kind of the only way to make original movies in that timeframe. The death of the EU would probably have been more broadly forgiven, if they'd really built something great to replace it for 7-9.