When it was first announced that James Gunn was fired from Guardians of the Galaxy Vol. 3, a lot of people started to consider who would be replacing him as director for the project. As it turns out, Disney may not have been looking for someone to replace him at all.
According to multiple sources from THR and Deadline, Disney had not met with any potential directors after they had fired Gunn from Guardians 3. This has led some to believe that Disney didn't want to fire Gunn at all, and they only did it until the heat would die down on him after the whole backlash about his tweets. Once the issue was forgotten, they would get him back onboard—which they did.
So far nothing official has been confirmed, so you take the info with a grain of salt.
Admittedly there was a lot of criticism that came Disney's way after Gunn was removed from the project. A lot of people had pointed out that the person who started the issue was purposefully trying to silence Gunn since he was so vocal about his political views on Twitter. It was worth noting that Gunn had already apologized for these tweets even before he was hired by Disney.
Then again, it's possible that Disney did meet with other directors and they just didn't make it known to the media. There were some rumors going out that Adam McKay was being considered to direct, but it turns out he would rather work on a Silver Surfer movie. Other fan favorite choices like Taika Waititi and Edgar Wright also said that Gunn would be their only choice to helm the film.
For now, Gunn is working on Suicide Squad 2 which comes out in 2021. No release date has been set for Guardians of the Galaxy Vol. 3.
See Also: James Gunn: Suicide Squad 2 is Still Priority Over GotG Vol. 3