This will be the second edition. It will be difficult for anyone to answer your questions.
But, according to my experience, you have to think the other way around. When we started the preparation for the rally, the biggest problem was getting people's commitment. Many people may be interested, but few will go ahead.
Therefore, if you contact any of the teams at an early stage, and give your commitment, you will have a good start point.
Of course nobody knows what the future will bring, but nobody sees the Dakar comming back to Africa in the short term. Furthermore, the dates are different and I believe the idea behind the rally is also different.
Even not a Dakar rally here, Africa is competitive. Doesn't matter how you look at it. It will take its toll. Everybody is different and have a different goal. I think the goal of all competitors is arriving at the Lake rose. We have many kms per day in hostile environments.
The choice of bike, is also very personal. My experience with big twins is they are good for the road and that's it.
In our team we have 3 WR450, 1 EXC530 and 1 DRZ. In Africa roads can have nasty surprises so you should stick to a sensible speed. On the track, depends on the rider's ability of course, but an enduro machine will do well in the rocks and sand and a big twin..................
Don't forget to contact the organization. They will be able to help you. They are very communicative. I also think that the rally will grow in the comming years making a more appealing route. More Mauritania (???)