Is this specifically written somewhere for these devices, or are you simply saying that there is now no need for certification for comms equipment that does not require installation? I'm trying to understand how you've reached your conclusion.
As far as Icom are concerned, their current transceivers are still not certified for airborne use according to their website.
In practice it is doubtful as to whether this would preclude use as a backup device: are you really going to resist using it when you've ditched hoping for SAR?
Cheers, Howard