Since "bug" MC-148600 has been fixed, gold farms like that one https://www.youtube.com/watch?v=l9oteFEj770 does not work anymore, as the newly spawned pigmen aren't angry.

In my opinion, those farms aren't too OP considering the number of blocs and works it needs to be built. That said, I would rather suggest to reset the anger of pigmen when the player die.