I think it is obvious that staying stationary all day (standing vs. sitting) will be bad for cardiovascular health. I also don't think anyone believed standing would suddenly make working for 8+ hours a day in front of a computer screen healthy.

However, with a standing desk and split keyboard (apple trackpad in the middle), I personally feel I can work with some semblance of decent posture. When I work sitting down, especially for long periods of time, my posture degrades (tech neck, etc.) When standing up with a split keyboard, at least my posture is linear and my shoulders are back. From the study, apparently the improved posture benefits do not carry over to cardiovascular health benefits, but I would guess it is still beneficial. Very rarely in the office do I see people sitting with good posture (It is possible, but takes more conscience effort), but I will often see people standing with good "upright" posture.

tldr: Article mentions nothing about posture improvements. That is what I always thought improved the most moving from sitting to standing desks.