My understanding is that "Masonic Education" in my jurisdiction is limited to a list of what the GL deems as appropriate material to use. I've seen the list, and I'm less than impressed with the overall selection. I hope in the future that they add to it. I'm not holding my breath for that though.
As far as some heavy hitters coming in to speak, that would be billed as a special event speaker. They could talk about what they want as far as I know. They would be from another jurisdiction, so I don't know what their limitations would be.
There are several Brothers on this forum from my jurisdiction. Maybe they know the answer to your question.