A:Answer TL;DR: The SWA-W700 subwoofer will NOT pair with HW-N950.
So, I bought the SWA-W700 from Best Buy last night and it DOES NOT pair with the HW-N950. The blue blinking light never turns solid blue even when ID SET is started on the soundbar.
I could not use the provided wireless dongle, since the dongle is USB-C based. The HW-N950 has a USB-A "Service" port on the underside. Even if I could find the adapter, I doubt the dongle can be used on the HW-N950. I'll be returning the subwoofer later.
On another note, I did confirm that a second PS-WN90 subwoofer (ie. subwoofer model of the HW-N950), can be added/paired with an existing HW-N950 set. So 2 subwoofers are possible on one HW-N950 setup.