I think you might be on to something with this Yamaha vs Suzuki talk....... but it's what one does better than the other. Suzukis are known to be great turning motorcycles which work well in SX because of the tight confines of the tracks....... but Yamaha's are known for their stability, which makes them better for High Speed stuff and rougher types tracks, or even outdoors. I think that Daytona is so rough and high speed vs a regular SX, that the Suzuki might just be a little too twitchy to run for 30 minutes at that pace with SX suspension and settings. Yamaha's probably work better at Daytona in the hands of a Professional SX rider.... but not as good at a normal SX.
Of course that is just my opinion based on what I know about the bikes and what the riders like.........
And I don't know if I see Reed leaving Factory Honda Backing, but if Factory Yamaha is calling with a clean sheet of paper again with the money in hand...... could be!