Hi all, I found the fix at least for me. So, first I tried uninstalling and reinstalling the Zwift Companion app, but that didn’t help. Then I followed Zwift’s instructions (which the forum won’t let me link to lol) to cleanly uninstall and reinstall the Zwift app on my MacBook (I kept ~/Documents/Zwift intact) and on first launch the macOS app asked to connect to local devices on my network. Sure enough as we all suspected, that was the permission that had been reset. Just, on the macOS side not the iOS side. My Companion app is now connecting and showing the map/dashboard.
Unfortunately, this also broke syncing activities into the iPhone Health app. And the two that were missed while this was broken don’t seem to be retroactively syncing.