I don't know what his ratio is on his predictions, but like what he said or not it doesn't take a genius to see that this is where things are probably headed. It's a way to make money, but not the right way. Will it affect new game sales? yes, of course it will, but it will have a much /more/ lasting effect on USED game sales. Right now publishers and developers get nothing from used game sales, and if they adopt this model then everyone who's playing their game online will have to shell out the subscription fee.
It may take years, but if every major publisher adopted this philosophy eventually used game sales would probably become so unprofitable for retailers who must drastically lower their prices and thus trade values to get people to buy used games with subscription fees.... Seems to me they're trying to kill 2 birds with 1 stone. More money for publisher, yes. Used Game sales, drying up but still providing them with more money than the zero they were making off of them before.
As for people buying older titles instead, that's possible, but there's a solution for that as well depending on just how 'hardcore' the publisher wants to be. Once the next generation of consoles is released, they could simply shutdown the matchmaking servers for the current console generation games. Wouldn't happen immediately, perhaps 18-24 months after to ensure a good adoption rate before they swap over fully, but business is business.
I'm not predicting any of this will happen myself, aside from agreeing that some games will have some form of subscription based multiplayer. That might mean charging for dedicated servers for 'ranked' matches to make hacking more difficult, or any number of other options. The rest is speculation, and certainly one possible way things could unfold. Would I like any of that? Nope, but I don't think anyone can deny that those steps are likely being talked about in some conference room somewhere.