Even so, I wonder how many high ranking WWII officers are still alive?
I’d guess not more than a handful.
VA Statistics show that TOTAL US Veterans is around 300k, a drop of 600k+ since 2015. Given that Officers, except for aviation, tended to be older and fewer than the rest, I'd say that there are very few remaining that ended the War at O-5 or above (Lt.Col. / CDR). My late father was an Army Major at the end and was only a year younger than Van Stockum and he passed at age 95 seven years ago.
One thing of note although probably not applicable to Officers, WW2 was the last conflict with a significant number underage GIs. My Dad had troops as young as 16 in Europe and sent home a couple who were younger. Still, after a single day of combat, they earned a CIB (Combat Infantry Badge) and would have Veteran Status (unless stripped).
The youngest documented, that I know of, was a Texas Seaman named Calvin Graham on the USS South Dakota at age 12 in 1942. When the Navy learned of his age, he was in the brig for 3 months, dishonorably discharged and stripped of his Purple Heart and Bronze Star. The Bronze Star was restored to him under President Carter, his disability benefits were restored by Reagan and his family got his Purple Heart 2 years after his death in 1992. If he were still living, he would be just breaking 90.