I think that reads more like confirmation that those games will all eventually be ported to PC. It's just not going to be part of the original development cycle. It seems like MS is perceiving some threat in the home PC space and that first party / 2nd party games is one way to help shore up dominance in home PCs. MS doesn;t have the 1st party capacity to develop exclusive games separately for Xbox and PC so they need to bring more Xbox games to PC.
I'd be surprised to see Halo 5 on PC, even though it was a Xbox/PC game right at the start it does seem like main sequence Halo should remain one of the essential pillars of Xbox and not be available on any other platform. Either that or now that MS owns Gears and is making it in-house Halo could go to PC and Gears can be the Xbox only pillar. It's a weaker pillar for Xbox, but if MS sees a need to really shore up PC with key MS exclusive games then Halo is a good candidate for PC.
“The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.” - Bertrand Russell
"When the power of love overcomes the love of power, the world will know peace."
Jimi Hendrix
