This isn't the first time we've heard rumblings about Vixen being on WB's radar. Those in the know that claimed WB was developing a Blue Beetle film (which is now confirmed) have also said Vixen and Hawkgirl/Hawkman have been discussed.
As for popularity/notoriety, I'd say Vixen and Bumblebee are pretty evenly matched in that regard. Vixen has been used alot in JL related media plus the CW shows and Bumblebee has been used in all TT/YJ media and Super Hero Girls.