The paper does explain these limitations and it would be wrong to assume that this means we can see/photograph through fog, skin, clouds... But a semiconductor laser can have a spacial coherence long enough to do holography so if they said the source was a laser and non-conherent narroband, I'll give them the benefit of the doubt and assume they did something to destroy the laser coherence. Spinning frosted glass beam interrupters and other techniques are often used to despeckle laser light where it interferes with the laser's intended use.
Speckle does occur with non laser light sources but it isn't usually as strong because of the shorter coherence length. Go outside on a sunny day and look at your fingernails or a piece of black anodized metal, you may see the effect of white light speckle interference. The really amazing part of this technique is that they did it with such a low-res camera. While 42 Megapixels seems like ridiculous overkill for a phone camera, it doesn't hold a candle to the typical spacial resolutions approaching 400 Gigapixels for holography film. Extend and expand the technique into higher resolutions, illuminate with coherent laser light sources and it will be a valuable technique for laser imaging as well as other things. What else has point light sources against a dark sky and obscuring translucent material? The starry night sky. I knew the day would come when finally astronomers can have their cloud filter!