The unknown chip is a Skyworks Si4707 NOAA receiver - that's the radio there. See Si4707-B20 Data Sheet (skyworksinc.com) for the datasheet.

Update: I have disconnected the strange jumper from the TEST terminals and nothing seems to have happened. I will update if I discover something different but so far it seems that they are only empty terminals

Interesting, playing around with it a bit, I managed to find something strange about the "Unknown chip with test pads":

I bought my WR120 second hand, (since in Mexico they are somewhat difficult to find). and trying to see if i could modify the Notification Tone to use the official tone of the Mexican seismic alert system, Compare the images. but apparently someone repaired it before or from the factory came with this. the "TEST" terminals are bridged with a wire to a pin below C21, and there is something strange about the arrangement in the smd solder between R48 and C6
the wire is glued to the pcb with some kind of paste (maybe hot glue or flux that has solidified)

-I leave you images: https://photos.app.goo.gl/PVBZw3s9sFFsGhUv6

I don't know if I disconnect the jumper from the TEST terminals or leave it as is?

The radio works but behaves somewhat strange when operating on batteries (these drain in a few months, the screen becomes dim but fluctuates to the rhythm of the message when listening is active)
 I do not know if it is because of it, but if you connect headphones to the external alert port you can hear the transmission faintly.

As an accidental discovery, it is possible to generate some strange behavior when inputting audio through the external antenna and cloning ports.
-I discovered this by accident trying to do an auto activation with windows audio and EAS tones, the strangest occur when changing the sampling frequency to 44100 and 16 bit audio, apparently the radio must have some built-in filter of bands, since more bits or frequencies seem unfazed, apparently Self-Act. it can only be done with old iphone