So out of curiosity, I decided to try out the passive again not that the update is out for PC. I thought that it might have been fixed and just not documented.
I thought wrong. Putting any amount of points into it still completely disables veterancy gain, meaning units will never gain veteran levels.
This is a pretty big issue.
P.S. Also on the topic of veterancy, it seems Ander’s Guardian and Retriever Sentinels are unable to gain veterancy. I don’t know if this is intended or not. (I do know that these units are very controversial right now, but all units really should be able to gain veterancy.)