"Watership Down"
From the article ...
"The BBFC continues to receive "one or two complaints" each year over its content, which includes scenes of rabbits fighting, being throttled and gasping for air."
So because of one or two snowflake idiots (or trolls) classic movies are now deemed inappropriate for children.
Just wait till they get their hands on all the old cartoons such as Bugs Bunny who is constantly being attacked by that violent Elmer Fudd, Tom and Jerry always fighting and getting the cat's face blown up, The Roadrunner and the Coyote with far too many violent scenes to mention here, Popeye and his spinach enhanced punches, and many more children's favorites from yesteryear. All must be reclassified to 18+. Think of the children!