I'm obviously just speculating here, since I don't have access to private information and don't know what transpired internally at Novara, but I think it's the result of both internal disagreements and audience capture.
In any case, I think that whole saga has really shown again that, although some on the left keep hoping they will be able to create a space for people who don't like identity politics and want to focus on economic issues, it's basically impossible.
The truth is that, although people on the left like to pose as people who are dismissive of post-materialist concerns, this is just larping and no debate about economic policy will ever come close to unleashing the kind of passions we have seen during the controversy about Arday.
Anti-racism and other identity politics issues like feminism are literally the religion of the left at this point and there is no room for any movement on the left that refuses to make a sacrifice to that god when asked.
Aaron Bastani and Michael Walker have been trying to make Novara more open-minded and less tied to woke shibboleths, without losing its left-wing orientation, and I think they've had some success. I'm not sure whether this is explained by internal disagreement within the 1/