There's no possible way for them to code that into the game without redoing the entire system. Raids are programmed to happen to players near a workbench. There's no way for the game to know the difference between a player in copper age or a player in padded armor because raids are decided based on boss kills.

If you have a server for multiple people to play on, you should never kill bosses unless it's as a group, and you must all be mindful of each other's progression and gear. If there are players who want to progress faster, they can do so without killing any bosses and triggering events. You can progress all the way to level 4 wolf armor without killing a single boss