I also try to research about the possibility of a postponement, but so far I haven't seen any sources yet. Maybe @Agbe can pointed us out to the source of this news? So that we can see if it true or just a rumor for now?
Just find the below article from Dan Rafael's post and it confirms the said postponement of the fight to January as per Tank Davis. The reason was not clear though but it maybe the venue i think.
WBA lightweight titlist Gervonta “Tank” Davis was supposed to make his sixth defense against Lamont Roach Jr., the WBA junior lightweight titleholder, on Dec. 14 at the Toyota Center in Houston.
However, multiple sources who would be involved in the event told Fight Freaks Unite that the fight will not happen this year. Even Davis himself said so.
Responding a message from Fight Freaks Unite asking if he could clarify the situation, Davis wrote, “January I’m hearing” for when the fight would happen.
After the WBA approved the bout in late September, both fighters announced the fight date and location on social media as did Premier Boxing Champions, which would have staged it as the main event of a Prime Video pay-per-view card.
Perhaps it didn't get a positive response from the boxing community that's why they are thinking about postponing the fight. And for us here, we wanted Tank to really get to fight big names but unfortunately, they are all not available, so in a sense, he needs to pick someone that he is willing to fight him and then agree with the money.
But it looks like getting Lamont Roach has raised a lot of eye-brows and yes, it could back fire bigtime on Tank. But we have seen elite fighters as well getting easy fights, but I guess they don't want to cut some slack on Tank because he has been really protecting his 0 for a long time and not facing elite and great boxers.