The possibility of Brady getting injured behind a veteran OL, given the 20 years sample size of incredible health other than one season, is almost certainly less than the possibility that Edelman will get injured on a punt return (concussion, re-injuring thumb, re-injuring foot), in my opinion.
If Edelman did suffer an injury during a punt return, the “Why the hell was Edelman returning punts when he is so valuable to Brady in the passing game?!” posts would fill multiple pages on this site. At some point in the season, maybe early on, maybe not, Gummer is likely to take over the punt return duties.
They have a need at the punt return and kickoff return position. It is fairly obvious that they have been trying to find someone to consistently give them production in the returner role for several years. In the coaches’ minds, Gunner could be a factor this season and the chances of him getting poached by another team were likely we fairly high.
In that sense, the decision to cut Hoyer and keep Gunner was neither foolish nor needless. A player with the elusiveness, innate vision and fearlessness that are necessary to be an elite returner is hard to fine. Based upon early returns, Gunner has that natural ability.
In addition, young QBs need reps in practice. Without Hoyer around, Stidham will hopefully improve at a faster rate.....the talent is there, the decision-making and pocket awareness needs to get better. Not having Hoyer around as a veteran to tutor him is a clear minus but hopefully Brady will be willing to act as a mentor as well.