My son plays soccer in the spring, but not the fall. He did have to give up travel soccer because the hours conflicted with gym practice and soccer wanted a commit to both spring and fall seasons, and attending all the practices. Fortunately, we have an inter county soccer league so he can continue to play and practice with other kids who might play a different sport as their main sport, or don't have as high a skill level of the travel kids. Its been good for him because he still gets to play and keep his skills, learns good team skills and can attend practices around gym. This way if he decides to give up gym once he hits high school, he still has a decent chance of making a high school team.
We are also really lucky that our gym actually encourages the boys to play sport other than gymnastics if thats what they want. Because we have a large team, boys can be flexible as to which days they practice. From what I understand this is pretty unusual in gym world. Our head coach is pretty laid back about allowing boys to choose their own paths. They all know that the more they practice, the better they will be, but for some boys gym isn't their primary sport. This year for the first time we had about 4 high school boys (15-18) who did JD 2. All of them were football players who wanted to do gym as a strength supplement, but they all competed and some of them did quite well. They also practiced together so it wasn't like 4 big boys practicing alongside the 10-11 year olds.