New twist in the plot: After 26 films, the Broccoli family and the Eon Productions are stepping aside. For the history of the series, MGM has been the distributor (occasionally taking on other partners) with Eon producing. MGM was acquired by Amazon who have been itching to get the rights for themselves, thinking the series has franchise potential (TV spinoffs and that sort of thing). And the Broccolis and Amazon have finally come to a deal. Eon remains a partner, but Amazon MGM will now produce the movies (and other media properties) directly. Of course, the Fleming estate famously have had nothing to do with the movies or Eon in, well, eons so that none of the books written by other authors (Kingsley Amis, John Gardner, Raymond Benson, and more) after Fleming's death in 1964 have been available to the film producers. Whether Amazon might try to patch up relations with the estate remains to be seen.
Which is all to say that casting a new Bond might now have to wait until Amazon gets things moving on their version of Bond. The idea of a Marvel-style "universe" around Bond seems a bit ridiculous given the series is tightly focused on one specific character, but suggestions have been floated in the past for stories about side characters like Bond's CIA buddy Felix Leiter and the Bond comics currently being produced by Dynamite Comics have gone there.
The other thing hanging over it all, and some are suggesting this is why Eon did the deal now, is that there is only a decade left on Bond's copyright, at least on the Fleming novels, which means that in 2035, the door opens for rival Bonds.