Dark rooms are forever illegal. Sometimes they naturally occur. Dark rooms suck mobs out of the overworld and place them into areas that can easily be exploited/funneled or misused.
Regular spawns (that have a monster_spawner block and occur naturally are generally ok, if they are modified to damage the mobs, block access to the leveler/etc - they are therefore illegal)
The ruling has not changed on this, we have not made any addition to the rules and if you have questions, always refer to the wiki/stated rules.