AFAIK the big problem without a case is Wifi/BT (and maybe an RTC) - that said if the vendors would at least get an class B certification for one pcb+case combination they could probably improve OEM shipments.
Some commenters say the Raspberry PI got a Class B certification without having a case - but it also has no Wifi/BT/RTC - so this could be possible.
Some commenters say the Raspberry PI got a Class B certification without having a case - but it also has no Wifi/BT/RTC - so this could be possible.