Absolutely right about lava itself - but I figured that it was a reference to the surrounding environment. A dual with Obi Wan across a hot volcanic landscape, with gaping fissues and holes to hot death - nothing wrong with that.
I'm just concerned that the decision will be made careless and with marketing and production lines most in mind. "How can we make the most money out of this concept?" rather than "How can we tell a story".
But then again, as someone else pointed out, it's Lucas's own work. If he soils his own sandbox, let him play in it.
My, I'm a grump today.