Alternative timeline is actually the beginning of the end by Chris H.

I think the story that’s unfolding is showing the audience exactly what happens after the end game. Whatever game Jacob and MIB are playing will cumulate with the island sinking (at some point in time) or quite possibly removing the island from history’s timeline entirely. The bomb seems like a likely candidate for causing the island to sink, but that would mean everyone on the island at the time of the detonation would have perished (and we know Ms. Hawking was still on the island) which is why I think the end game ties into how the island sinks.

The island exist outside of time, in its own pocket, which leads me to believe the timeline on the island has to play itself out (2007) but the after effects of the coming war could reverberate throughout time and space.

I believe the ‘alt/future’ timeline will culminate with Jack fixing Locke (the Real John).

As for the game, think of it as a massive chess board. When players are killed, they are placed in an ‘out of bounds’, they can still be heard via the whispers but cannot interfere with the board or pieces on the board.

What the resolution is, how it’s reached, and what it all means in the greater sense of the show mythos is beyond me right now.