If you don't swim in order to conserve energy, then that policy should be in place regardless of how the team performs the first day.
If the "nobody swims" order is negative reinforcement for poor results the first day, that is counter-productive.
The original post led with the team having gone 0-2, and in response the coach told the parents no swimming -- the implication being it was punitive.
I've been on so many of these trips as a parent I've lost count. My kids have played for coaches who were authoritarians and coaches who taught skills and to have joy for the game.
I was a terrible college baseball player. The reason I went to practice every day knowing I had no future and little hope of playing in meaningful games was because I just enjoyed the mechanics of the sport -- whether practicing or in games.
When you take that joy out of an 11 year old, that is usually permanent.
If you’re on a travel team, spend that much money & time on a sport, the LEAST you could do is respect that coach, who is probably coaching for free, enough to follow his rules. I’d you don’t , you’re teaching your child that authority means nothing. Anyone really involved in sports know you don’t swim when you have games.