I don't think they saw O'Hoppe as a potential elite talent, he's a little stiff athletically to excel as a defensive catcher, and if you move him to 1B/DH/RF his hitting may make him a good but not special player.
Rojas has five tools and has the potential (that dirty word) to be an exceptional CF.
Marsh and Rojas are both more risky than O'Hoppe, who is a good bet to be a solid hitter.
Rojas of course is still unknown, and Marsh has the tools to be as good a hitter as O'Hoppe, he's still only 24 but has plus power, plus speed, but missing that year in AAA raises questions in terms of how good a hitter he'll be down the road.He has both flashed and struggled in the majors, and that makes him the kind of player who's a mystery box - maybe Long can fix things and he explodes onto the scene next year, maybe those flaws are innate.