Ahh. I tried searching but didn't see anyone mention it.
It may even do audio as well but given I am running through the AVR, the signal's not getting across. If I knew when it'd come up I'd try with it switched to the TV speakers and see.
I actually like the feature honestly and think it is great how Panasonic set it up to work on other inputs like that. Genius. Sadly here it seems they don't use it as often as they should be. For example they have modes for Severe Thunderstorm Watches and Warnings but I have yet to see EAS used much for those. Especially around here, severe storms tend to do quite a bit of damage for some reason.
I did some digging on the new digital form of EAS and they've made it pretty intelligent it seems. Or at least designed it to. It can trigger a tuner to switch to a different channel in the case of needing extended info that cannot be conveyed in a short message such as a text crawl.