They might. I wouldn't be shocked honestly. As tech keeps pushing the boundaries eventually they will start having games that work so well with the computer playing the part of the GM there will be no need. How soon that happens is anyone's guess though.
I think I'm going to have to take the exact opposite stance here. As technology keeps pushing the boundaries of social interaction, facilitating conversation and cooperation from anywhere at any time, RPGs will experience a golden age like nothing prior. I hope it'll be D&D that does this, but it could be anyone, even a current unknown.
I don't believe AI will ever eclipse the living DM, at least not until I have a robot butler and machines headline comedy clubs, but I think I know what you're alluding to from a rules/calculations standpoint and I think Mearls addresses this need to return to the DM as creative font AND arbiter. For many of us, though, I don't think that's a problem, but he's talking about making it the baseline assumption of all games... tricky if you don't have a skilled DM. Just one of the many balancing acts he's left with.
RPGs through social media is the natural evolution of a very social hobby, with many benefits and really no draw backs (you can still play in person, too). I've played online since high school, and it's provided me with steady, creative games, and a certain ease of play/interaction that live games weren't able. Now, more than ever, I have the tools to run some really visually games, with all manner of short cuts and aids, though it worked even back in 2000 with mIRC and FreeDraw (I still use mIRC, actually, hehe).
I see people all over playing turn-based games on phones, handhelds, and consoles, as well as live matches, throughout the course of their days and in their free time. There is an essential human element, and a spirit of cooperation or competition, that really engages us. I think that's the heart of RPGs, as well, which gives me hope they'll be moving hand-in-hand with social media into the future. Right now we're seeing the awkward first steps, is all, as old media companies try and utilize the confounding new medias in a way that engages the public. Like I said topside, so long as there's a love of fantasy, science fiction, horror, imagination in general, there'll be people working to unite our loves and technology.
The nice thing, is, when they do, there will still be a need for places like EnWorld and people like us, familiar with the roots, adept in gaming, even if the particular methods have changed. There will always be such things as a great game, that feeling we get, plots, NPCs, treasure, monsters, traps. That's not going anywhere. All that changes is accessibility, which should really only threaten the abnormal elitists.
*leaps over Dancey and onto the pulpit* Let go of your fear, my friends! We are not obsolete! We are COMPATIBLE! Social media, technology, will breathe MORE life into this glorious hobby.