It is unknown as of yet whether Kvitova who was number three seed; behind Ashleigh Barty and Simona Halep has an injury. Or whether she is just taking the extra time to prepare for the Australian Open.
In addition, Angelique Kerber who was next to be seeded will now take that spot. Finally Kerber will now be replaced by a Qualifier/Lucky Loser in that section. Also another player will be given an opportunity to play in the competition which acts as a pre cursor to Melbourne.
https://twitter.com/AdelaideTennis/status/1216275771561410560