This is all quite simple for me. I've been playing Halo since November 15, 2001. Halo 1-3 was legendary, no question. I really enjoyed ODST. Reach and Halo 4 were (overall) misses, imo, when you compare them to the first three. This is mainly why I sprung for the MCC - I'm getting everything I ever wanted in one package and can play this for the foreseeable future. This is not an issue of loyalty for me because I'm not going to simply buy something if it doesn't seem like a worthwhile investment on my end.
Based on my experience with Halo 4, I'm not very excited at the prospect of a Halo 5. The game, imo, has become too saturated with gimmicks like loadouts, weapon drops, sprint, etc. This series thrived off it's simplicity in arena style combat. It was easy to learn and hard to master. Now, it's becoming more and more like the typical unbalanced, throwaway shooters, CoD and BF. The golden age has come and gone. The modern FPS genre is going nowhere fast.
Now, as far as the MCC is concerned, obviously they're going to keep working on this until it's flawless and I'll be happy to keep it in my collection. I am thankful for what Bungie and 343 have done for this series, but loyalty has it's boundaries. Halo 5 will definitely, without a doubt, be the first game in the series that I will not be purchasing unless the reviews are so off-the-wall insane that the game is literally rewriting the rule book, like CE did 13 years ago. Master Chief's saga ended at the conclusion of Halo 3.