The system described is called a groyne. Not new or unique at all but in the right conditions it is remarkably effective. Different locations work differently due to sand source & currents --- should one decide to use such a system it might be helpful to begin small and see the results before jumping in whole hog and possibly making things worse instead of better.
After all --- the island was growing bit by bit all by itself before we got here .....
PS - a friend of mine had one in Placencia that worked very well indeed - she was sued by an neighbor who felt it was a bad idea, was forced by the Supreme Court to remove it --- and the properties both north and south of the groyne lost significant beach. Then again, Placencia is built of river wash not coral sand.