Without any kind of context, the quote doesn't say anything about plans to move Marshall back to QB. Considering the position was recruited as if he wasn't going to be at QB and the move back to QB didn't happen before spring practice, and only after CC asked to be moved, I still see no reason to believe this move was planned as opposed to just a reactionary measure to a poor back up QB situation. It was also reported, in the AJC, that CC could possibly move back to QB, but nobody seems to think that is even a possibility. Because barring a disaster it isn't.
You're right, although it appears he was more used on special teams, and an article I found mentioned something similar with the guy that came before him, Hampton, although the rosters I have found listed him as a QB even as a freshman. That being said, that practice has pretty much stopped as none of the QBs at GT have done so, and the last 3 navy QBs, Dobbs, Proctor, and Reynolds have all been QBs all the way I believe. Considering where navy was when Johnson took over, I think it's more likely that practice is a result of the state, and nature, of navy football rather than an active choice. Once Navy got more success that hasn't happened, it hasn't happened at GT, and based on media guides didn't appear to happen at GSU, at least under Johnson.
Revere was the starting QB at GSU Johnson's last 2 years there (00-01). Media guides list him as a QB all the way back to his tr fr year though. Before Revere was Hill, who was always a QB while Johnson was there, taking over midway through 97 after an injury to the starter. Hill was listed as a QB as a redshirt fr in the 96 media guide. Maybe it happened at some point, but it doesn't look like it was when johnson was the head coach
Both moves make sense. They moved Jordan because they thought CC was the future at QB, and didn't need a dedicated third string QB, while realizing that he was athletic enough to eventually be a starter at another position rather than a career backup at QB. Byerly gets hurt, they move him back. CC asks to switch positions, so they keep Jordan at QB. Jordan still isn't likely the guy going forward so they switch Marshall to throw something at the wall and see if it sticks. I think it's likely we either see TM redshirt this year, and if he stays at the position then it's a good sign that he'll take over, or if he doesn't, I'd almost be willing to put money on on of the rs. fr. to take over. Although Johnson is so in love with seniority that it's possible it won't be right away.