The standard on all 4 apps has always been anyone over level 250 can be listed by all players above them for any reason including no reason. It's just a strategy of the game. Higher levels out of range can not just attack you but they can put you on the hit list, axe slap, pistol whip & punch.
For example, if a higher level player punches you & you attack back, You are automatically put on their rival list for up to 24 hours until they kill you or time runs out. If you attack back, the 24 hour period is started over. Remember, if you set counter attacks they do count as an attack putting you on their rival list as well.
Again, this is a form of strategy such as being coaxed into a fight or they may see you fighting one of their clan, mob or squad members in the main feed. Players will also list other players simply because they are bored or they may be trying to get the hitlist achievement completed.