If they did exit and theres nothing to replace it, I'm interested in Plume right now. http://www.theverge.com/circuitbreaker/2016/12/5/13837804/pl... I like the size of the pods, it got good reviews and the price isn't horrible. Put the router in the basement; a pod on the patio, family room and 2nd floor hallway and that'll blanket the house. We've always struggled to get a strong wifi signal on the patio while streaming via Airplay and in the summer, we try to spend a lot of time outside. I may do it anyways...
http://appleinsider.com/articles/16/12/21/apple-airport-firm...
I'm almost thinking that they might shift things towards the Apple TV as a "Apple Home" kind of thing. Hard to tell.
If i was going to replace the Airport Extreme that I have, I would be going with a Ubitiqi edge router of some sort and one of their access points. The stuff seems well supported and has a decent community behind it, in addition to being reliable and making the pretty graphs that I want. :-)
The app and hardware touchscreen are really simple and usable. They're missing a few pro settings/configs though.