School boards have changed. Some have gone farther beyond reason than others. Also some administrators are more "ridiculous" than others when handing out punishments.
Not knowing anything about the location of the school, it is hard to know how far toward the "ridiculous" this punishment goes. For example, if this was an inner city school where gangs are a problem, it may be justified. However, if we are talking a rural district where such actions aren't common, it was definitely overkill.
I remember an incident from my high school days, definitely long ago (graduated in 1971). It was either 69 or 70 near halloween, when we had a "costume" day. One young man who loved to push the envelope, came as Pancho Villa complete with a huge sombrero and carrying an unloaded Win 94.
He was intercepted by our huge assistant principal who after verifying the unloaded status of the rifle simply confiscated it for the day and explained that it wasn't an appropriate part of the costume for school.