This would be a good idea. You already have players who already attempt different ways to do a fight just for fun. They wouldn't need to implement this at launch of a raid, but could add it in the patch after, when they'll have the hindsight of having seen the common strats people used to influence whatever challenges they put out.

This is partly why Second Coil Savage worked so well because they were able to adjust the mechanics of the turns so that people were forced to approach it differently compared to the common strats used for Second Coil (LoS Devour, Renaud stacking, T8/T9 solo tanking).