Bob Iger:

“Their interest was in creating a series of films that are Star Wars-based, and we’ve actually been talking to them for a long time,” Iger said. “They’re focused on a point in time in Star Wars mythology, and we’re taking it from there."

So, not necessarily a trilogy. They would seem a perfect fit for the ‘Old Republic’, to take the mythology back in time. Potentially creating something similar to the MCU with fresh new characters and timeline that could then go on to have their own ‘Star Wars Story’ spin off films.

We cant remain with Imperials Vs Rebels forever and I am sure Disney are aware of that.