I haven’t been involved with Halo for several years now. Things were going pretty well from a canon point of view until 2010 when Reach came out. That horse is very beaten and long dead.
In any event, that unfortunate incident not withstanding, what is the current state of the Halo canon in terms of consistency?
I’ve also noticed that The Fall of Reach was reissued earlier this year. Has it changed? The 2010 releases of that book and First Strike made things better, but there were still issues.
Aside from the inconsistencies between Reach and Fall of Reach, there aren’t any major canon issues I can think of. Bungie’s approach to the lore was that the games came first, then all other material came second. 343 on the other hand views all lore on an equal footing. Both approaches have advantages and disadvantages of course. But given how 343 is handling lore, I don’t foresee any major inconsistencies going forward (the TV show not withstanding).
To answer your question about The Fall of Reach. It does have small changes as before it was reissued the number of Spartan IIs recalled for Red Flag and the number in Red Team were incorrect and were adjusted accordingly to fit perfectly in the canon.
As for the inconsistencies between Halo Reach and The Fall of Reach I’ll let Mr Toa Freak himself (Halo Canon) explain, the following link will hopefully take you to his video
Reach Timeline Video. P.S As it says in the description of his video, it’s not official but could be a possible explanation using original cannon material.
To discuss any further inconsistencies, I can’t think of any as outstanding as this among fans, except for maybe the Elite design of the Arbiter, but that is non-canon and the new H2A cutscenes accurately depict how he should look in Halo 5. I’m hoping maybe they’ll make a quick redesign to fix the Arbiter in Halo 5 but I’m doubtful. To just add a further note, 343i has been really good at handling lore as they have been at the mantle of Halo for a good few years now and I think they have finally found their stride.