An idea to help casuals/bads

I know there's a lot of debate on here about the difference between a "casual" and a "bad." I always considered myself a "casual" who would rather pug than join a guild and be forced to be on a game at a specific time and day.

The new dungeon journal is a great step in the right direction to helping people like myself, but it cant help me get into a pug with out that damn achievement. So my question is, has it ever been talked about adding instanced raid bosses?

What I mean by this is adding an instance that can be qued for or something with just a specific raid boss that would drop no loot. You and 9 other npc's could go in, fight the boss learn its mechanics and perhaps earn an achievement that says "hey I know the fight now." You wouldnt even need to kill the boss or even come close, maybe just a few minutes of an npc tanking it and a few npc's keeping you/the tank npc alive or depending on your role you healing the npcs while you learn the fight etc. It seems like a lot of work on blizzards part, but its something that would help us "casuals/bads" learn fights and also help us get into those pug raids that people still demand achievements for.