He says that it takes billions of years for a galaxy to form. I don't know where he gets that from. I'm not an avid student of cosmology, but what drips of information I have absorbed described galaxies forming very soon after the big bang. And mostly, or all, with supermassive black holes at the centre.
He seems to be talking about what people thought 25 years ago. Obviously the James Webb is showing some unexpected stuff, that's what it's for. Before Webb, it was more speculation what the early universe looked like.
It seems to be emerging that all, or nearly all galaxies have a supermassive black hole at the centre, and the way that they detect that is by gravitational lensing. This isn't new stuff, it's what people have been saying for ages. Maybe the James Webb is showing that that's true for the very earliest galaxies. I haven't heard that there was any theoretical reason why that shouldn't be the case.