Yes, this is all normal behavior. The parents are letting the juveniles explore on their own because migration is nearing. The parents will chase them from the area so that they will join other juveniles and start introducing themselves to opposite gendered juveniles. The point is that this separation from the parents will lead to an introduction which will lead to pairings/bondings and new families for the future. Once the pairs are bonded, they will return to their nesting area on the return migratory path, establish their own habitats and start a family.

The pulling of the plants allow the young swans, the adult swans and dabbling ducks to eat the vegetation and plankton that they might not otherwise be able to reach under the water. New scientific research shows that this does not deplete the biomass and actually helps attract diverse waterfowl, especially those species that cannot reach this rich food source. The Regal Swan