Thao, who is normally a super flyweight (51-52 kg), has decided to move up to super bantamweight (54-55kg) to fight for the belt.
Thao will need to beat Dib, an International Boxing Federation champion in 2011-13 and International Boxing Organization champion in 2008, if he wants to make history as the first Vietnamese boxer to win this title.
The 34-year-old from Australia has racked up 45 wins, including 26 knockouts, and six losses.
Thao shot into fame after defeating Indonesia's George Lumoly to become the first Vietnamese boxer to win a WBC Asia title in November 2017, and has not lost a bout since.
The 27-year-old's winning streak rose to 12 when he defeated the Philippines' Ponciana Remandiman 3-0 in the World Boxing Organization Oriental Youth Title Match's men category on November 3.