Twitter user IdleSloth84 — described as 'Xbox News Guy' on their profile — posted an apparent photo of an image showing three Xbox consoles side-by-side — the Series X on the left, Series S on the right, and this supposedly new Series V console in the middle.
This would suggest that the Series V would be a middle-ground console, more powerful than the Series S but perhaps less so than the Series X. Another possibility is an all-digital version of the Series X hardware, given the clear lack of a disc drive.
The existence of a "Project Edinburgh" has already been spotted in Xbox OS files and was referred to by Windows Central tech editor Jez Corden back in July — could this new Series V console be what the project title refers to?
Of course, this image should be taken with a very large pinch of salt, as it could very well — if not most likely — be a fabrication.