Last night telling Alexa to "turn on Apple tv downstairs" or "Turn On Apple TV Upstairs" resulted in her not doing anything and telling me the hub wasn't available (something like that)

It seems to be fine today but I know Harmony is a thing of the past and we are lucky to have it running this long.

Can I natively add AV equipment into the EISY and create a 'scene' that essentially turns on the gear like Harmony does?

I have the scenes as a routine that turns on the gear, sets each piece to the correct setting, and changes the Insteon lighting to whatever scene it should be.

Just asking to prep for the inevitable...

Yes. I do that. You can use network resources to control A/V equipment. Some devices can be controlled directly over IP network and devices that are IR only can be controlled with the use of IP to IR converters. Look at the Global Cache Flex IR devices for that. There may be cheaper alternatives also, haven’t looked in a while.

Right now my setup is a Harmony hub that I give commands to through Alexa devices and going to the AV gear

(receivers, apple tvs, blu ray players, fire sticks, etc)

I've just checked out Global Cache and I have some reading to do.

Correct me if I'm wrong but it seems they are trying to be able to connect anything to anything? Like Harmony but with a wider range of devices and possibilities?