First off I’d like to say I understand that fish farms can be extremely over powered  and something should be done that changed the drop rates within them. But personally I believe they should still work after all we can create all the other red stone devices/farms to get free items heck iron farms are rediculous! 

But none the less, afk fish farms no long work if I remember correctly as of 1.4 holding down the left trigger (Xbox one bedrock user here) to fish while looking at something like a music box, trapdoor, etc no longer reels in fish. Yes it’s exploiting the game but changing the drop rates of the rarest/high level enchant books would help greatly simply make it twice as rare to get like mending or lvl 4-5 enchants on books while fishing. Yes I’m sure that’s easier said then done but fish farms are still active on java edition and are used by streamers and pro minecrafters constantly. It seems unfair to not treat this as a bug considering it isn’t broken on java edition which is typically looked at as the main edition of Minecraft..

I personally think this is a bug to have completely broken afk fishing on bedrock edition only.

but if this was done on purpose to remove afk fishing entirely maybe the community should be told that it was a purposeful change as it was never addressed within  the update changes and/or fixes.