I think they didn't do a FO set before its release is because the most logical thing to do is the Mantis, which would be like a $160 set of a ship that has only been in the one game, with Mando, they released the iconic AT-ST, which would sell well with or without the Mandalorian figures and the paintjob it has. Its a very easy set to customize into a classic OT vehicle for fairly cheap, so if the Mandalorian had failed, the set wouldn't have flopped. If they released the Razor Crest last year and the show sucked, that set wouldn't have sold well at all. But as we know, the show was a success, and i wouldn't be suprised if the razor crest is one of the top selling sets this year. Back to FO, the game has been released for nearly a year now and was a hit, so if we get a Mantis it will likely come next year, maybe in January if they started designing right after the game came out.