You wouldn't need to worry about it in that regard, they wouldn't split the devs up in any way that would affect the Xbox version, especially after MCC. They would hire new people or put people to work on it that currently have no tasks etc. Halo would defo sell well in this day and age on the PC compared to Halo 1 and 2, it's been a long ass time since then, PC popularity has increased by a shit load and the hype for it would be unreal.