Yes, of course it's anecdotal. I haven't done a blinded, peer-reviewed study. But as noted, I have a LOT of experience at it, so I think my anecdotal knowledge is pretty relevant here. Have you just run a camp for 20 new players, many on the spectrum, a number of whom were enrolled by their parents and didn't even know what D&D is? I did.
And it is not unrelated at all. The discussion is about adding subclasses at level 1, which would add significant complexity to the first game for new players. That's the whole point of the sub-classes: you have the basic class and then you get to specialize by adding complexity. Thus, one way to help D&D be easy to explain and learn is to hold off on adding that complexity until players have a little experience under their belts.
It's a moot discussion anyway, though, so probably not worth much more effort. They aren't going to make fundamental changes such as adding sub-classes at level 1. That's not what OneD&D is. But Pathfinder is a thing, for those who feel like they really need more complex character generation right out of the gate. It's a good game, too.