The astonishing thing with the Halo franchise is that 343 kept being given chances to go again, and again, when it clearly just wasn't working. By the time they get round to releasing a great new Halo people that loved the original will be taking out their pensions.
It cannot be understated the extent to which the console industry, including third party publishers and devs, needs Sony and Microsoft to both stay competitive. In that light the drastic moves being done at MS are long overdue, but maybe not sufficient. It's also an open question if consoles (outside of the Nintendo universe, which is a very different audience) have a future at all.