Just look at the impact KOTOR, KOTOR 2 had on gaming.... they shaped ALOT (not all) of things in rpgs and mmorpgs (not everything) and have a huge fanbase...then factor in the newer kotor games on pc and platforms and smart devices...
Hk-47
Revan
Bastila
Nihlus
Canderous Ordo
And many many others definitely have a place.
The fannbase is established, and it endures the test of time....
KOTOR was an introduction of a fresh look to the star wars franchise and it was a HUGE success...
Jar Jar Binks is an example of an initially negative result. Although i think time has given him some (keyword some...ie darth jar jar) street cred
Rebels is an attempt at replicating the phenomenal success (fresh approach) of the KOTOR games and story. But has not been as successful as KOTOR, nor as quite as despised as jar jar is/was.
Disney made rebels to emulate a successful business model and i think it overall has been profitable, but not even close to as much as KOTOR.
That being said, the most logical business strategy is to go back to KOTOR, a tried and true formula that is guaranteed to yield some (potentialy huge) profit...and in the meantime, rebels may gain traction. Until then KOTOR is not a bet, but rather a calculated investment. Disney is smart, and Canon/Non-Canon/EU are just fancy ways of saying product testing and consumer control...there may be branding issues with some EU content...and we all know how disney handles copyrights and acquisitions...we dont know what happens behind closed doors. But can only speculate disney will force choke the profit out of there investment in a way that maximizes profit + legacy.