Dallinor on 30 April 2014
Imagine MS advertising a game from the makers of Halo? It would naturally seem like an extension to their first party. I think from the onset Sony saw an opportunity to pull the game away from them and to try and establish a connection to their brand with the title. Bungie/Activizion might have even preferred this move, as they know Bungie/Halo fans exist on Xbox platforms already, but this would allow for a very high level of advertising to new gamers on a platform they weren't reaching before.
Either way, given that the game was initially not meant to be releasing on Sony platforms, until the sequel, this turned out to be a very surprising move.
