If there are multiple gamers playing on the same server, then it's an MMO. And I don't understand what your saying why not to.

I was agreeing with you on always being open to speculation (as long as it fits into the universe) and your examples. And COD, BF, GOW, Halo, and such and such manage multiplayer by organizing players into a single server so no: All MMO's use single-servers, but not all single-server games are MMO. An MMO is described as having always one persistent world, with multiple players always occupying that world you're in regardless of where you are. In a game like WOW, you could always locate another player if you just search around or wait for one to come where you are. Bungie (and there are videos where they specifically describe this if you look online) has firmly stated "This is Not an MMO," since players phase in and out of this persistent world depending on certain areas. You could literally play Destiny and its story, without interacting with another player. They also described that this game will have MMO elements, like having multiple players onscreen in large worlds, leveling systems, and customization, but to call it an MMO would be odd because the experience is nothing like an MMO. To put it in perspective, think of Mass Effect in first person, where you occasionally go into areas where other players are in. This is what Bungie has described it as word for word (except for the Mass Effect thing, that was all me). Look it up if you want

Well there are hub worlds, but you can avoid people all together. Lets agree to disagree.