Yes, there are indeed RYF-certified laptops supporting free WiFi firmware, but they are now vulnerable to Spectre, Meltdown etc, and not fixable. So unfortunately this is not very secure to use them...
I recall running into issues with WiFi firmware from Purism. I installed the prop. driver and got some improvement. Although, I ended up upgrading the wifi chip altogether in the end.
There are at least the handful the FSF RYF certifies.¹
Unfortunately you do appear correct about Intel WiFi not having Free software support² (though that adapter certainly should).
¹https://ryf.fsf.org/categories/laptops
²https://h-node.org/wifi/catalogue/en/1/1/Intel-Corporation/u...