I find it hard to believe they will do something like this, however, given everything we know of Microsoft and their business practices, not only in the gaming industry, but over the last two to three decades, this rumor is plausible.
Using financial incentives to undermine the competition instead of building their own brand sounds like something Microsoft will do. Not to mention, any publisher who accepts such a weak and petty deal clearly does not share the best interests of their developers and that is to sell the games their developers create. And I must mention, if Sony is also a participant of such deals, they should be called out.
I hope this rumor is not true, but if come Monday it turns out to be accurate, I think hardcore gamers should let the industry know that such business practices does not help the industry grow, but rather it stifles competition.