If we're being honest, all this change did was codify what every witness deep down already knew to be true anyway: The real ones in charge are the GB, and that's it. The whole "all anointed remnant are part of the F&DS" thing was just a nice mental salve to soothe the minds of the R&F, giving them something to point to so they could say, "See! We're not a cult, we don't follow any single leader, or even a small group of leaders!"
In reality, everyone knew that there was no way in hell the GB was ever going to accept a call from Joe Crazy, who just happens to drink the wine every year in some middle-of-nowhere congregation, claiming to have some new insight from the Holy Spirit on Ephesians 1:10.
I do think the GB sensed a potential threat to their leadership in leaving the definition of the F&DS so broad, and preemptively changed it to prevent some future uprising.