The rumor originally started based of the past history for Microsoft's Xbox One exclusives:

Insomniac holds this rights to the IP.
Many "Xbox One Exclusives" have or are being ported to the PC.

Now Sunset Overdrive has been seen marketed for both the Xbox One/PC.  The rumors with no merits now finally hold more weight.  

Here is an official response on the issue.

Mistakes like this would be extremely unlikely if a PC version didn't exist or wasn't in the making.

This is very in line with what Microsoft is doing with it third party developer exclusives and it's going to be an interesting topic going forward.

Until a PC version is confirmed, I'm just going to assume it is going to remain an XBO exclusive.

Just like Ryse and Dead Rising 3!  History generally repeats itself.  I do admire your dedication to the Xbox teams' word.

I am extremely happy about a potential PC version.  This game screems play me at 1080p at 60fps.

I wouldn't be surprised if MS did this. They really don't know how to hold their exclusives and it's sad...

Hoe many times are people gonna post this mistake today?

Crytek/MS said a lot of times that Ryse was an Xbox one exclusive. Yet, here we are today, so i wont be suprised. Its not like Microsoft owns the game, so its very possible at some time

So what you are saying is mine has new information from twitter and is in the PC section because it's discussing the possibility of a PC version.  I look in the PC section for PC news, is that weird?

It is so obvious that it will eventually come to PC.

I wish Phil would place all the other promises and other to do list stuff and simply focus on keeping Xbox One exclusives and make them stay exclusive, it doesn't do him or anyone besides those who don't want the console any favours, it's no wonder that we're at this point where those who never wanted the console are able to feel super confident that the console will lose it;s exclusives, Phil really needs to work on that asap either by creating Xbox One exclusives and PC exclusives with their PC side because although I game on PC myself as well as consoles nothing pisses me off more than buying a console and having it lose it;s reason to exist, especially to those that just hate MS and want to have their cake and eat it.

The sooner he gets on top of this the better it will be and the over confident people wanting their exclusives can nut up and buy the damn platform.