Unless foods have been left out at room temperatures for too long, refreezing is not an unsafe practice.
Assuming the rice and veggies were safe when cooked, then promptly frozen after the meal, they will be fine.
The rule to not refreeze food is more a matter of changing the texture of the food rather than making it unsafe. The veggies could be a little mushy when defrosted and reheated.
"If you want to make an apple pie from scratch, you must first create the universe." -Carl Sagan