But backtracking a bit, someone who has worked with Disney licensing did say Disney tend to craft these things in their favour. There will be no shortage of publishers or even platform holders who can make Star Wars games, but EA will be hard pressed to find another Star Wars currently. So Disney has all the leverage.
Unless somebody has also dealt with EA licensing I don't think you can reasonably say how favorable the terms of the contract are to each party. If Disney/Lucas want an exclusive license holder capable of turning out AAA games on a semi-annual basis, there probably aren't a lot of third parties that can fulfill that end of the bargain. Single-platform holders do not reach a wide enough audience, so Sony/Nintendo/Microsoft are kind of off the table. Which leaves you with a choice between Activision, Ubisoft, and EA. Disney might have a heavy hand with toy and merch licensing, but that's because there's a million people willing to make that stuff in mass quantities. Choices are slimmer in gaming.
I think what also gets discounted is that Star Wars is only considered a heavy-hitter IP in the wake of something like Battlefront selling 14M copies despite a lukewarm critical reception. At the time EA negotiated their deal, Star Wars was not a very strong gaming IP. The Force Unleashed got a huge budget and a huge push but didn't sell half as many copies as Battlefront. To this day major publishers are still somewhat wary of licensed properties. I don't think EA got a sweetheart deal or anything, but the leverage you're talking about wasn't really solidified until Force Awakens and Battlefront released. I have my doubts that the exclusivity contract contains some kind of "Get Out of Jail Free" clause that lets Disney drop EA without any repercussion. No decent lawyer or executive would remotely stand for that.
I think what motivated Disney to go with EA is what will motivate them to keep EA. Disney does not want to destroy SWTOR, and EA can turn out products on a regular schedule with big production values. Whatever deal Disney has with EA they likely will not get with Ubisoft or Activision. Those publishers probably don't see a need or a desire to divert resources from their core IPs like Call of Duty, Assassin's Creed, Destiny, FarCry, Overwatch, Warcraft, etc. Those franchises sell 10M copies easily and Activision/Ubi don't have to share the profits with Disney. Part of what drives the EA/Disney relationship is that they need each other. Ubi and Activision would probably like to publish Star Wars games, but not on the terms Disney wants to offer.
Like I said previously, if Disney burns the shit out of EA, how can they possibly negotiate favorable terms with someone else? They'd almost have to go back to the ad-hoc piecemeal licensing scheme they used to have with Star Wars, because nobody is going to pay for Star Wars exclusivity if there's evidence that Disney is just going to abandon them when the road gets a little bumpy. The fact that they have leverage over EA is all the more reason to keep them around, because they aren't going to get that kind of leverage with another AAA publisher.