That kind of seems crazy to me, considering OpenBSD has worked perfectly fine with every wifi capable device I've tested it on. Granted, most of them were older machines.
Is this just an artifact of FreeBSD primarily focusing on server hardware rather than consumer/end-user stuff?
Basically no one supports Broadcom SoftMAC WiFi cards very well, but OpenBSD just doesn't. I have a 2015 MacBook Air with a BCM4350 where the recommended fix is to go buy a FullMAC card from a similar vintage MacBook Pro and just cope with the fact that the card barely fits in the case and can't be secured properly.