Each of those games had come and gone on the 360 having their own "moment" in the sun for about two years before the next game came out. That collection wasn't a set of "new" games to the platform launching all at once but this Halo one would be.
I'm not sure what the point is here. Ok, well this time there is no Halo multiplayer on Xbox One. As I say later in this post, that is fruits for literally millions of people to play Halo multiplayer, and those could easily be divided among each of the games and still give each an ample supply of players.
That wasn't the only reason it didn't happen, a limited dev timeframe and no network infrastructure in the original game were a big part of it too.
Of course they would have had to do it. That's what a lot of people were planning on buying it for. Not doing that killed a huge reason for purchasing the game.
A lot of people have said that for Halo 2 they won't need to create an online infrastructure, since 2 already had one, but I think they do. Both 2 and 3 had pretty terrible netcode. I think they really need to completely rehaul it. I mean, just take notes from Killer Instinct. I see people saying that things netcode is "LAN-like." That is what Halo 2 needs.
This next part is to you as well:
Gears didn't get a traditional trilogy pack. It included Gears 1/2 and the All Fronts Collection which was all the DLC for Gears 2.
I find it weird how Microsoft didn't do proper "GOTY" versions for Gears 3/Judgment. Pretty sure it was the same for Halo 3/Reach?
That still doesn't disprove my point. Ok, it isn't three games; it's two games. That's still multiple multiplayers.
Plus, think about it. Halo has an insane number of fans. Each game would have a huge share of people playing it. I mean just look at the number of players Halo 3 got during games with gold. If the number of people saying they will seriously buy an Xbox One for this is any indication, there will be ample players on each of the multiplayers. Plus; it's not like everybody just plays one multiplayer. I would play all three, alternatively.
In addition; who's to say that all three will get their own multiplayer. What if it's just all three campaigns, and one redone multiplayer after the fashion of 2 and 3?