I've read an article in which author auggests that "there have been claims that Fleming’s publisher, Glidrose Productions, was against the idea of further Bond books after the author’s death in 1964." That's the first time I've found such info. Considering Bond's growing populairty at the time, it's diffucult to imagine they'd make such a decision.
link to the article: https://overland.org...e-andrew-nette/