Unless these rooms have separate ventilation and they have a highly developed and comprehensive program in place to identify and separate kids in the early infectious (but not always highly symptomatic) stages, it ain't going to do much more than make a few people feel like they have done something.

Quarantines tend to be one of those "just common sense" things that often end up being more of a ritual than a science. Viruses have become well adapted to spread before people are acutely ill.