Honestly, regardless of how good they have been for us thus far, both are not what we need if we want to achieve something. Especially in the EPL, Blind is a weak link and can be, and has been, targeted by oppos. Mata won't be getting the number 10 anytime soon and on the win Mourinho would probably want speed.
While the "news" might be rubbish, as someone already said, it's an educated guess because it makes sense. In perspective, it all depends on who will take their places. I wouldn't mind them being sold if we strengthen significantly but if it's just an average signing, might as well keep them. Doubt anyone will be unhappy if we sign better players in their places.