I’ve no knowledge of this cultivar, but 9b is a large zone, and microclimates within it will of course abound. Zones are a great starting point for ideas of what plants will easily succeed, but they can extend considerable distances and the temperature will be colder/milder the farther north/south someone is located within one. You could get away with mangos and sensitive avocados (and many other tropical plants) for several years in the southern end of 9b with only occasional need for serious protection. Hardy cultivars and plants might not need any. Here in the northern end of 9b, plants damaged at 28-30 degrees need foresight for planting location as well as protection during the medium to hard freezes that occur every 2-4 years.
Along with location in a zone, microclimates also play a massive role. I know of a couple 40 foot mangos just 10 miles from me that fruit considerably in most years. These trees are located just 15 feet from a large lake, receive full sun from southern exposure in winter, and are surrounded by a stand of 50-60 foot live oaks on their northern side. Basically, the perfect microclimate for this area, and these trees are basically living in 10a.