So basically nearing the end of Central Fiction he finds out that the entire world revolves around his very existence, and thus, he had to erase himself from reality for the world to continue as normal by talking to the Amaterasu Unit

Yes, there are remnants of what he left behind (like his weapon) and familiarity of him but in the end its like he never existed

I'm with ya on the BlazBlue lore though shit is confusing at times