It’s not an entirely rare occurrence for friends of Housewives to drop in and out of filming, though noting their absence could gauge a fandom’s reaction to them not being around on the show.
Tanya Sam is not an official cast member of The Real Housewives Of Atlanta, so it stands to reason that had this announcement not happened, fans could’ve gone on not realizing anything was amiss.
Friends of the show are occasionally in the bullpen to become castmembers eventually, so Bravo could deal with this situation based on how fans like Sam on the show.