Now if you want discussions, that's a whole different matter. I've used PowerPoint for discussions. Usually one slide to frame the discussion and a second slide I leave up that has the goal of the discussion -- that is, what are we here to answer. You could just as easily do it with a printout or on a whiteboard, but a PowerPoint is often logistically easier. The keypoint though is that a discussion should have a clear goal. If you can't put the goal of the discussion down in a sentence you probably aren't crisp yet as to what you're doing.
And really, if it's that light, couldn't you have just had the discussion via email?
On one hand, it seems like it might be a good idea for the purpose of cross-functional education.
On the other hand, one runs the very real possibility of someone effectively taking a 101 class on a complex subject, scratching the surface and making decisions based on their limited understanding of another group's area of expertise.
"A little learning is a dangerous thing" - Alexander Pope
Meetings should be for discussions, not education.
I think he's correct that PowerPoint encourages the latter and discourages the former.
However, I think he's wrong about having people present about things outside their area. That only encourages them to do research into things they have no business in.
Instead, only call meetings when decisions need to be made, and only let people prepare the facts needed to make those decisions, not presentations.