@Erik1242 Definitely not automatically transferred- that would be really disrepectful to guests, who have booked on the basis of the reviews the previous host earned. They need to be given a choice as to whether they want to keep the booking or not. In your case , they probably will be fine with keeping it, as you are already a host with hopefully good reviews.
So the previous host has to deal with this- contact the guests and explain the situation, and if they want to keep the bookings, you can contact Airbnb to see if they can assist with transferring them.
If you don't want the bookings, because you can't vet the guests, then the previous host should contact Airbnb to get them all cancelled.
It would be really rude to guests to just have their bookings cancelled with no explanation.