You are asking the question backwards. We do not have all the facts, but it seems that because Disney knew RSR would be super popular in June 2012, and because they suspected it would break down a lot - which it did - when RSR opened they decided to limit the number of FPs given out each day. This kept the standby line from becoming even longer than the typical 120-150 minutes it was that first summer and the typical 90-120 minutes it has been ever since.
They also initiated for the first time ever EMH at DCA which allowed folks to ride RSR an hour earlier.
With all of that, they decided to make RSR disconnected. That is the real "change" as it is virtually unprecedented at Disney parks. I never heard of it at WDW but they did seem to do some funny things with EE when it opened in 2006. Now after two years Disney seems to be bringing RSR back to normal with all other FP rides (except for CA Screamin which has been disconnected the last couple years for some unknown reason).
The result will be the same as all other FP rides. FPs will last longer in the day so more people can get them. The morning rush will be diminished of folks know they can get FPs longer in the day rather than having them run out in the first 60-90 minutes.