I cant' give you a proper answer but using Yachtworld pictures I do notice this change happened around 2014, which I believe coincide with the mid-lifecycle update Amel did when they also revamped the dashboard with different switches etc.
The new solution does look cleaner although I still feel the lack of a proper traveller is a shame, even though they did bring back the rod-kicker which is dearly missed on our A54.
Given the way they rigged it in the latter solution I do think you should be careful with the main sheet when the boom is out. It may catch something and get snagged if the pressure on the sail is momentary lost because of sea motion
For abandoning initial solution, it does expose quit some forces at a point of the boat that has limited natural structural rigidity. Given how many boats use arches for the main sheet nowadays I suppose that is not a big problem.