If the unannounced other AAA title that is going to be developed concurrently with Cyberpunk (see
here) is in fact a Witcher game, then I think the people working on it would be mostly different from the team that made TW3 and then moved on to CP2077. Although the original lead writers/designers/director would likely still be involved to some extent. Similarly to how Blood and Wine was made. A new "Witcher" team may also make sense when the next game is not a continuation of the same story anyway.