I agree that they should finally get around to boosting the FoV, but your numbers are wrong.Please 343 reverse bungies shitty fov decisions (h1 was 90 and it went downhill from there, h3 was 70 or 75).
Halo 1 was 70 horizontal, in 4:3 mode. For CEA's 16:9 they horizontally expanded the view while holding vertical constant, which made it 86 degrees horizontal.
Halo 3 was 70 horizontal in 16:9 mode, although 55 in 4:3 mode.
Since Reach, all mainline releases have been 78 in 16:9 mode.