This is a step in the direction of making the server much more friendly. PVP can be fun, but it's mostly a nuisance. It causes arguments, anger, and, worst of all, players leaving. People don't want to play and build on a server where part of the community wants to cause other players stress and anger.
Intelli stated that the mist was implemented to emulate a new hostile mob: The Player. It adds a survival aspect. Since then, hostile mob spawns have risen. Therefore, I argue we don't need the mist anymore.
There's an ambiguity in the use of lava, snowballs, etc. in the nether and end as indirect pvp. In these cases, I suggest these constitute illegal pvp as it is in the overworld.