Had to go back through the SD-WAN Design guide. Some particular notes that I pulled out is this:
BFD is used not only to detect blackout conditions but is also used to measure various path characteristics such as loss, latency, and jitter. These measurements are compared against the configured thresholds defined by the application-aware routing policy, and dynamic path decisions can be made based on the results in order to provide optimal quality for business-critical applications. SD-WAN Design Zone
As stated by Batuhan Mutlu, it allows for the utilization of multi-path links but also allows traffic to be preferred based on metrics (similar to MPLS-TE) while taking into account links that are not capable of TE like characteristics.