the halo collection is overrated, i think.
The question is rather:

Does microsoft Need to Counter "bloodborne" and "the order 1886" ? I think not.

Well about Bloodborne and Order 1886 i agree, thats y i didnt include SO but we cant overlook CoD AW has a potential factor

I don't know... I don't think Halo MCC will be such a threat to the PS4! It wil boost X1 sales, yes, but it won't be that much of a threat for the PS4!

I don't think Sony needs to counter this game. They already know it is going to sell well this holiday, and to waste money on a campaign to divert some sales during this time of the year is pointless. They are riding on having the hot system right now with enough games to please new buyers.

Halo MCC will help MS out during the holiday season, also with the "secret" bundles Pachter mentioned. Any ground Sony loses in the holiday rush can be leveled off during the 1st quarter of 2015 with the release of Bloodborne, and The Order (I hope this game is good).

I personally think if The Order is marketed heavily, and is met with great sales but horrible reviews by gaming journalist, and gamers it could hurt Sony for a bit.
Look at Destiny right now, I know alot of people bought into the hype, but I have not seen a game (some with a console) hit the used market this fast, which points to alot of disappointed gamers, showing signs of buyers remorse for jumping to next gen.

I think new IP's will be met with skepticism by casuals that will cause them to wait for established IP's to come out.

Nope.

PS4 has the momentum. Don't forget with the army of exclusives PS3 could not stop Xbox 360 momentum. So it will be very hard to stop the momentum.

they dont need it.

I'm sure Sony will release a GTA V bundle since they have no other bundles. Think about it, Nov 18 right before black friday, will sell tons. Also it will probably be for around $450 so when they look at the CODAW bundle for $500, parents will go for the cheaper one. Honestly I think Microsoft messed up by making it $500 again.

One game collection isn't going to put a dent in the PS4 momentum. It may boost XB1 sales for a week but then sales will return to normal. There's very little point in Sony trying to counter a blip, they'll wait until something substantial happens before they react and it doesn't look as if it's going to happen this year OR next year. Even a XB1 pricedrop doesn't look like it will turn the tides for MS.

I am honestly getting confused by the amount of faith some seem to have in halo MCC on the XB1.

And as for your COD:AW, I think people are also mistaken the fact that because COD usually sold more on the 360 its an always had xbox bias marketing its an xbox game.

Here's a little something to consider;

PS3 NA total = 28.62M
360 NA total = 47.37M (~40% more than PS3)

Call of duty MW3 (2011) = PS3, 5.4M and 360 8.7M (+40% approx)
Call of duty BO (2010) = PS3 5.8M and 360 9.3M (+40% approx)

Do it for all the other call of duty games, the games simply always just sold to the tune of the available install base. This is why I am never of the inclination that COD is an "xbox" franchise.