Current customers will get ODST for free when it comes out. Future customers will have the option to buy ODST. This is actually unbelievably amazing news. Forget the fact that this is part of a compensation plan. ODST is coming to MCC! This is megaton-level stuff. Reach shouldn't be far behind. So MCC will end up being a completely comprehensive collection of all mainline Halo games when all is said and done.
As someone who hasn't bought MCC yet, this greatly pleases me.
All of this is of course contingent on 343 actually fixing the original MCC. I hope they can - I won't say I think they can, because they have been mostly incompetent up to this point. But this is like if, say Mario Galaxy Collection on Wii U was broken for two months, and Nintendo came out and said "We'll fix this as soon as we can guys, oh and, you guys will get Super Mario Sunshine as compensation". Or if Zelda 3D Collection on Wii U was broken for two months and Nintendo gave early adopters all the handheld Zelda games for free.
Sure the game still isn't fixed but for now I'll enjoy the awesome, eventual prospect of ODST and Reach being a part of MCC. I don't even care about ODST being free - I didn't buy MCC and I will never buy it as long as it's broken. But if this thing gets fixed, and it ends up having ODST and Reach as a part of its package? Lord have mercy.