Yeah, but article's saying there wasn't a draft, much less multiples.
It sounds like there were Lucas' notes - which Kennedy decided not to use all that much. Some ideas from those were given to Arndt, who came up with a treatment out of that, and got the screenplay job. From there, Arndt spent a year coming up with ideas - that never actually became a completed draft, whether due to Kasdan/Kinberg interference, or due to just never figuring out a narrative to string the moments he was coming up with together. Then Abrams comes in, Arndt gets dismissed, and Kasdan/Abrams spend six months coming up with a narrative that actually uses some of the details from Arndt & Lucas, but is primarily their own story. In fact, it sounds like Abrams' having a blank slate to work from was a huge reason as to why he took the job.