Our local council have just done the hedges, they do them now as the birds have finished nesting. They are done in late winter / early spring too, before nesting starts. Our local roads are so narrow that if they left the hedges till winter nobody would be able to get along the roads
The one place locally that I can pick wild damsons is only reachable because they have trimmed back the lower hedgerows too. Hedges here are high enough and wide enough for the birds to do okay from the berries that people and machinery can't touch.