You're assuming it was an imprecise use of the term, and I think the further clarifications from OP indicate that it's more likely that it was a precise use of a loaded term.
At sub-HS ages (at least), I'd also disagree that it's strictly the coach's team. Recreational baseball (and I use the term broadly to include travel ball here) at the ages the OP clarified is primarily a cooperative affair between coach, parents, and players. As another poster suggested earlier, how would you feel if the coach had brought in 9 new players and cut the guys he started with? Or if he ran his team all year long using that methodology? How long do you think such a team would remain viable at 13/14?