The point that WoW was making is that MS hasn't lost that 6 Billion entirely, that 6 Billion has bought them their image and their brand. If they were to drop out of the market they would give up 6 billion in equity that is stored in their games division's image and brand.
Its sort of like poker in the way that money you've bet is in the middle of the pot and the only way you lose your claim to that money is by folding or losing the hand. So with MS starting to show profitable FYs it would be silly for them to fold...especially since unlike poker this market is not a zero sum game.








