That’s interesting but I wonder what exactly are they basing that on. The book itself is already in the public domain in the United States and Canada (since it is a US show filmed in Canada). Additionally the interpretation of Captain Hook is no where near close to the Disney film portrayal or the play both of which are still under copyright. This is the wiki article on public domain…
But since ABC is owned by Disney wouldn’t that make Once Upon A Time essentially a Disney production then wouldn’t they have some leeway in possibly using Disney as an influence?