I think the kind of people who would take homeopathic "vaccines" aren't the kind of people who would have taken precautions anyway, not unless forced to. You could maybe argue that they were endangering children by sending them to school, but really the danger would have been with the non-vaccinated child.
The only really significant new risk would be if a non-vaccinated homeopathic child was around a child who legitimately could not be vaccinated, but that's dependent on specific circumstances.