I understand your position Nesrie, and I understand your concern. However if you're only ever going to purchase a game once you have a signed contract stating multiplayer servers will be left active literally forever, complete with ongoing support for your life time and that the company who's developed the game and the game that has published the game - and any digital distribution providers inbetween - who have made this agreement will never close down then you're never going to purchase a game again.
Battle.net can be closed down, meaning Blizzard's title's online multiplayer would no longer work. World of Warcraft's servers will be closed down one day - probably in about forty years - so does this mean you shouldn't buy either title now? Of course not. Closing down offical servers for an unpopullar game may be a dick move, but it's entirely understandable. The game simply wasn't very good to begin with, and as a result didn't really develop much of a community to warrant keeping the servers active. If EA Games made a policy for shutting down the servers for each instalment of a series once a new instalment was released to force their multiplayer communities to migrate - and they will, believe me, when trying to charge a subscription fee for single player games fails - then your fear would have some form of rationale behind it. As it stands - you're basically saying that any company that produces any game has to stay in business and provide their services until the ending of the world for you to get on board. That's simply laughable.