The way I see it there are multiple reasons for high kicks (not just hoping for a mistake by the opposition catcher);
The longer the hang time the longer you have to get to the opposition catcher and any support players, extra time to get your defensive line set. With the new down town ruling that's even more important than previously. Fullback and wingers these days are pretty good at catching the traditional end over end kicks, so kickers are aiming more getting their defensive line set, trap the opposition deep in their own territory. Obviously this relies on everyone being on the same page, fast line speed whilst maintaining a strict defensive structure. This was one of the contributing reasons why we dominated possession in the Trial 1, we had something like 65% possession in the first half and prominent field position.
The floating bomb also has the above tactical advantage, but it is much harder to execute, with a correspondingly smaller margin for error. The advantage is it is much harder to catch as its landing zone is more unpredictable. Plus even the slightest breeze moves it around making it even more difficult to get into a catching position. That's unpredictable for the catcher but also unpredictable for the kicker, much harder to get it into a small target zone. You don't really aim for the corners with a belly kick. The advantage of a floating bomb is the higher chance of the catcher misjudging it, dropping it, knocking on or simply letting it bounce from the fear of dropping it. In that it is more of an attacking weapon, but it does have a higher risk profile.
Watching Trial 1 it was pretty obvious that the Coaching Team wanted to see and test the "teamwork". Particularly maintaining the defensive structure that they have spent the off season drilling into the players. Hence the dominance of the high end over end kicks for field position, trap the bastards in their own red zone, fast line speed. straight line, no rushing, no lagging, no one out of line, maintaining contact with you closest team mate. Which is hard to argue wasn't extremely effective and impressive.
Always a Bulldog