In The Sims 4, there is a simple way to stop werewolves from popping up in wolf form all over your save. You can head into Game Options, open Pack Settings, and turn on the setting called Limit Werewolves to Moonwood Mill.
Once that option is on, werewolves still exist in your game, but you will not see them running around in wolf form outside their home world.
This setting does not confine werewolves to Moonwood Mill or prevent them from traveling. They can still visit other worlds like normal Sims. The difference is that they stay in their human form when they are elsewhere most of the time.
In other words, you will rarely see werewolves running around in full wolf form outside Moonwood Mill. They can still visit other lots like any other Sim, and if they are already there, they can still get enraged and lose control.
Even when that does happen, it is pretty rare. Most of the time, werewolves outside Moonwood Mill stay calm and low-key.
As long as you are not actively engaging with them or stirring things up, the chances of seeing one go fully enraged on a random lot are very slim.
Some players do not mind the chaos and leave the option turned off. Others flip it on once werewolves start taking over every neighborhood. Since the setting is initially disabled, you must manually enable it to achieve calmer worlds.
Not everyone loves this feature, though. Some Simmers feel like it singles out werewolves unfairly. Vampires like Vlad or Caleb still show up everywhere, no matter where your Sims live, which makes the restriction feel a bit one-sided to some players.
I think it would be really nice to have the same kind of control added for other occult types. For example, celebrities often wander onto lots at the worst possible times. Having more control over who shows up and where would make the game feel smoother.
Happy Simming!