Variable aperture won't add anything to current phone photography because they sidestepped it with software. They can already bokeh (pleasingly blur) the backdrop of a portrait by comparing the results of one lens to another and adjusting accordingly.

Where I think the analysts are wrong is where Apple might use it though. Three lenses is unsightly. I reckon they will reduce the iPhone down to a single, variable aperture lens. What they will then do it combine this with a variable zoom prism lens similar to the Sony Xperia VI giving a zoom range of 35-105mm (1x to 3x zoom).

What this would lead to is a Pixel-style bar on the back to accommodate the optics which whilst down to preference, I think looks rather nice.