Correct but less than helpful. I'm now convinced that the first Intel 8265 wireless card I bought was counterfeit or defective. Fortunately I was able to return it. The second 8265 card I bought has antenna posts that are the right size and shape.
Unfortunately, my attempts to connect the antenna wires to the counterfeit card damaged one of the caps. The new card, however, came with external antennae so I was able to cut and splice one of those caps onto the wire in the laptop. This required stripping and twisting hair-thin coaxial antenna wires, then adjusting my soldering jig to hold them close enough to solder. Even being quite myopic, I needed a loupe to see what I was doing. Amazingly, it worked.
I have, however, ordered a new antenna for my XPS-15 and will install that when it arrives. By watching YouTube videos I learned that detaching the display from an XPS-15 9560 is relatively easy compared to earlier XPS-15 models. Once the display is off, removing the antenna cover and replacing the antenna appears to be quite easy as well.
What astonishes me about this series of events is what seems to me an incredibly stupid engineering decision to reduce the size of antenna wire caps and posts down to the point of absurdity. The ones in older laptops didn't take up a significantly larger space and are infinitely easier to connect and disconnect. I would really like to meet whoever made the decision to shrink them. Something I learned very early in my software development career that also applies to hardware is:
IF IT'S NOT BROKEN DON'T FIX IT!