Question - is the idea that James Bond/007 is a code and character that changes person confirmed in universe lore, or is it just assumed?
In the books it is definitively one man, and over in film from Connery up to Brosnan is all one man.
Sometimes this is more explicit - so we see both Connery and Moore actively reference their dead wife, Tracy - who was killed in Lazenby's single film. Moore even visits her grave in one film.
Dalton and Brosnan don't
directly reference Tracy (which makes sense - referencing an event from a 1969 film in 1997 feels nuts), but there's nods in dialogue and their performances (like slightly sad stony-faced stares when asked if he's ever been in love/married) that are veiled keeping of that continuity. You've also got stuff like Brosnan being in possession of the Goldfinger car at the start of GoldenEye, or him using some of the Connery-era gadgets in Die Another Day. In the end, they just sort of had this continuity but made Bond a man out of time in that he never aged, and the characters around him were recast or their roles adjusted when they got too old; so Q is more of a father figure to Brosnan and Dalton than he was to the others, and Moneypenny was recast et.c
With Craig's Bond it becomes more complicated, because Casino Royale was sold as an outright reboot of the series, so everything from the past was jettisoned and considered a separate 'lore'. But then three films in they started breaking the rule a little... so Craig has the Goldfinger car, complete with gadgets (which suggests that the old Q existed before Craig's day?), and it appears in this new film he's also going to have one of Dalton's old cars, an 80s Aston. It's these things, post-reboot, that have given some the cause to speculate that maybe going forward James Bond will be a codename granted to a new agent.
