I've lost both, tubeless tires on drop-center rims, and also tube-type on multi-piece rims, without a drop center. I can't say that between the two I recall a significant difference in maintaining control during the flat.
Myself, I guess I'm not convinced that during tire failure the tubeless tire falling into a rim's drop is a significant issue. Even watching the video it doesn't look like the tire bead had any particular tendency to "walk" toward the rim's drop or to the installed band. In fact, I sort of wonder that if a tire is going to leave the wheel, the sooner it can be jettisoned the better the rest of the ride down will be. But, I haven't conducted any scientific studies either.
Ted