Just a thought here from Iger's perspective...
Disney got Lucasfilm in October 2012. Filming on The Force Awakens didn't start until Spring 2014. So this was likely all blue sky work anyway. The article even stated there hadn't been architectural drawings done yet.
Frozen opens in November 2013 and is a huge hit. There's nothing in the parks. Iger pushes something through which eventually opens less than 3 years later (RIP Maelstrom/ Epcot). Now if you're Iger, and you had a time machine, wouldn't you have wanted a Frozen land already under development in 2011?
So In late 2013/early 2014 Iger is realizing it would be really nice to have lands/rides ready to go when a movie opens. The article states WDI started working on the land when Lucasfilm was purchased ('12) and they worked "for a few years." So about 1-2 years into the work on "Tatooine land" Iger has this epiphany. Meanwhile, at this same time Scott Trowbridge is announced to head an internal "Star Wars studio" at WDI.
Kennedy poses a valid question but I don't believe she initiated the thinking.
Also keep in mind that around this time they have a very good idea of how good (?) the sequels might be ($$). I wonder if they had focus-grouped any of the film's concept art and characters like BB-8.
However, it was a gamble to choose between new and old trilogies when they could have had both.
They could have treated it like Liberty Square and Frontierland, where one end of the land/park is the older location/time (Tatooine) and the other end is a planet from the newer history and sequels. It could have even been the same size as what we got. Put Smugglers in Tatooine and Rise in the sequel side. Makes sense as Smugglers and the Falcon feel retro anyway.
This way they can sell both sets of merch and both a retro and modern take on the same IP.
To me, the key to all of this is that they took a pretty big gamble on the concept of "your adventure" and the hotel. It's harder to develop that concept out when half the land is in the past and half is in the present. So the question of what timeline to place the hotel experience ruins it all and forces you to choose old or new, not both.