As someone with aphantasia, I'm also not convinced that is the cause. I can draw better than average from memory, and used to be quite good but haven't practiced for many years.
There are also animators and artists with aphantasia[1].
My spatial recollection is particularly good - I can sketch out precise diagrammatic drawings from memory much better than I can do artistic drawings.
So while it's not impossible that not having aphantasia would've been a benefit to him, I don't think there's much evidence that it's has any big effect on the ability to draw - something that also fits Ed Catmull's experience on surveying his old employees in the article mentioned.
My wife has aphantasia, is fluent in Japanese, and writes the language better than many of our friends who still live there. She was just forced to learn the stroke order, etc when learning the language.
Aphantasia causes many odd issues for her but the ability to write complex languages or draw are not one of them.
There are also animators and artists with aphantasia[1].
My spatial recollection is particularly good - I can sketch out precise diagrammatic drawings from memory much better than I can do artistic drawings.
So while it's not impossible that not having aphantasia would've been a benefit to him, I don't think there's much evidence that it's has any big effect on the ability to draw - something that also fits Ed Catmull's experience on surveying his old employees in the article mentioned.
[1] https://www.bbc.co.uk/news/health-47830256