Dubois captured the interim title with an impressive win over Filip Hrgovic last year and was elevated to world champion when Oleksandr Usyk vacated the belt.
The Londoner legitimised himself as a world champion when he upset the odds by dismantling two-time champion Joshua inside five rounds at Wembley Stadium.
Parker earns a title shot after a four-fight winning streak, including impressive wins over Deontay Wilder and Zhang in his past two fights.
In October, Beterbiev defeated Bivol by majority decision to become the first undisputed light-heavyweight champion since 2002.
Many ringside observers felt Bivol, who suffered a first career defeat, should have been awarded the decision.
Former super-middleweight world champion Smith was stopped by Beterbiev for the unified light-heavyweight titles in January but returned to winning ways against Carlos Galvan on Saturday to earn a shot against the undefeated Buatsi, who claimed the WBO interim title on the Joshua-Dubois undercard.
Ilford-born Sheeraz, 25, has won all 21 pro bouts with 17 stoppages. He withdrew from an ordered fight against WBO champion Janibek Alimkhanuly to take on Dominican Adames, who has lost once in 25 bouts.
