The named titles include Avatar: The Way of Water, Avatar: The Seed Bearer, Avatar: The Tulkun Rider and Avatar: The Quest for Eywa.

Despite Disney CEO Bob Iger remarking Avatar 4 and Avatar 5 have not yet received a go-ahead signal, Landau is positive the five-movie saga will have seen the light of day under Disney after its $71.3 billion acquisition of 21st Century Fox.
Avatar mastermind James Cameron confirmed that those four titles leaked by BBC in November were in fact real.

Confirming the legitimacy of the titles, Cameron told ET with some reluctance, “All right, here’s what I will tell you. Those titles are among titles that are in consideration. And no final decisions have been made yet.”

Cameron said in 2012 he did not want to call the first sequel “Avatar 2,” explaining at the Visual Effects Society Awards, “Jake is not an avatar anymore, is he? Maybe we’ll call it Na’vi.” 
The first Avatar sequel is slated for release on 18 December 2020.