Dennis Gassner is returning. He mentioned it in passing during an interview with ICG magazine whilst discussing his work on Blade Runner 2049.
“With franchises, you have to honor the established elements while meeting audience expectations. I’m about to do my fourth James Bond film, and acknowledging the efforts of Ken Adam and others is a big part.”
I can’t find it on their website, but they do have their Deakins interview from the same feature if you fancy a look. http://www.icgmagazine.com/web/humanity-2-0/
Things is - the director is always hired before these people are, as it is directors choice. so whilst Gassner, as their new go-to production designer following Lamonts retirement, doesn’t indicate who the director is as much as, say, Nathan Crowley would, it does mean EON do probably have a director hired, they just aren’t ready to announce yet.