No, that’s part of the PDM circuit, but the GND pin of that circuit is common to the antenna chip’s GND side. And since the PDM is empty, it’s safer/easier to solder a wire there instead of the the chip’s side contact. This is by no means a replacement for the antenna chip, just augmenting the RF strength of the existing chip antenna.
If you want to have a larger impact, replace the antenna chip with a better circuit/setup. The wire I added gave a 10db increase in signal inside my home which allowed me to get a reliable connection in a farther room which I was not able to get before.