Yes, the availability restrictions that you have set in your Booking.com rate plan will be copied to your BedBooking rate plan when you create your connection. All Booking.com independent rate plans, including prices and availability restrictions, will be downloaded to BedBooking unchanged. From the time of the connection, you will manage the pricing and restrictions of these rate plans in the BedBooking Price list, but everything that has been set in the price list in Booking.com's Extranet up to the time of the connection will be displayed in the BedBooking Price list.
Please note that if you enable the "Commission and Availability" feature after creating a connection, Booking.com rate plans using this functionality will have prices based on BedBooking prices and existing availability restrictions will be replaced by availability restrictions that belong to BedBooking prices. To learn more about this functionality, read the article How does "Commission and Availability" work?