I’ve done a fresh install using the June 2020 disk image yesterday and have been setting it up using ethernet cable.
I want to move it over to Wifi and have gone into My OSMC > Network as usual, however, the Wireless option on the left hand side is missing? It only offers Wired, Bluetooth or MySQL.
The short answer is no the wlan0 interface didn’t show up there either. In raspi-config it stated “No wireless interface found” when trying to configure WLAN
However, it prompted me to further dig and I removed the microSD card overclock line (overclock microSD guide) from config.txt and rebooted and it now works. In My OSMC the Wireless option is now available.