So they reported on software built into iOS 15 before iOS 15 was ever released and we're supposed to take this as fact?
This article is pretty much hooey and proves nothing as it's from August, before iOS was officially released, before iPhone 13 series phones were released and not one other real reviewer has suggested this exists in any way shape or form in iOS 15.
Further, the article, which is clearly not based on any fact doesn't suggest the cameras remove lens flare. As we all know, cameras cannot remove lens flare. This is about post photo processing. I have software for post photo processing that I can use to remove lens flare. It's typically available in any really good photo editing software like Adobe Photoshop, and it's called a healing brush.