The Dalton and Brosnan Bond films were released during an era of VHS and home rental, unlike the Connery, Lazenby and most Moore ones. (I mentioned the JDB appearances only being 2 movies apart, but of course, given the 1989-95 hiatus between Licence to Kill and Goldeneye, that was nearly as long as Maud Adams’ gap) People only got to see Bond movies every few years on tv, not whenever they wanted.
Plus not only did the likes of Gray reappear in different roles, but between You Only Live Twice and Live and Let Die, Bond was not played by the same actor in consecutive films, nor was Blofeld between YOLT and Diamonds Are Forever. Blofeld failed to recognise Bond in On Her Majesty’s Secret Service, despite their meeting in the previous film (and OHMSS also has its fourth-window-breaking “this never happened to the other fellow). And then DAF makes no mention of Blofeld murdering Bond’s new bride in OHMSS.
Edit - even as recently as LTK, in which Felix Leiter had a major role, rather than bring back the actor who’d played the role in the film immediately beforehand, and who was a contemporary of Dalton, they had him played by the much older actor who’d previously played him in LALD, simply because Cubby Broccoli bumped into him in a restaurant and spontaneously invited him to reprise the role!
So, continuity was much less rigid back then, compared to an ongoing series where actors and characters last seen in a 2009 film are appearing in the next release.
That is not to say that I am in the “Doom will have a Tony connection” camp. I think it’s at least as likely that he won’t. As I said very soon after the announcement, I’m surprised that more people aren’t commenting on the fact that he played multiple characters in The Sympathiser and I think he is equally capable of doing so in the MCU. But at the same time, neither do I think it’s out of the question that he might be back as some form of Tony Stark variant. I think an open mind should be kept.
