The best argument I have seen for what creates the haze is the timing of the dry hop. dry hopping during fermentation creates polyphenols that bind to proteins, remain in suspension and create the haze. Yeast in suspension can be partially responsible and I have even heard a theory that hop oils may coat the yeast cells disturbing their ability to flocculate. But, as
@beersk mentioned, the idea behind a NEIPA isn't to put a large yeast starter in a glass. The primary source of haze should be due to the process.
I have done a NEIPA without flaked anything and it ended up very hazy. After experimenting with them quite a bit, I'm convinced that the timing of the dry hop is the biggest factor.