I run the normal rPi 3 image on zero2w and its what you talked about, a no-wifi image.
Now the real questions is for @stintel . I have followed the discussions over the years but I dont remember what was the trick to make wifi work after installing openwrt. I never really needed the build-in wifi.
@stintel if you have 5 mins to spare can you let us know how we can get the wifi working from an latest stable image?