The latest news at this time is that United have pulled out of the hunt for De Jong because they still believe that even though there are many threats from Barcelona for De Jong, he will still stay until his salary is fully paid.
I'd consider Manchester United an unserious club for staying this long in pursuit of Frankie, i mean, this is a player that has some problems with his club Barcelona because of unpaid wages and other whatnots, the player has also declined moving to Old Trafford, thus what is the need to continuously chase him, that is bad business, when one player is taking the club too long to sign due to difficult reasons that prolly can't be changed (like in Frankie's case), the best thing to do is to move on to other targets, especially when you have a limited time left in the transfer window.
Having said that, if you watch how City do their transfer business, you'd understand the difference between them and Manchester United, City were interested in Cucurella, the deal was going nowhere and they moved on, that is what i expected Manchester United to have done; now they have just two weeks till the end of this transfer window, the club has already started in a disastrous way this season and there are no good signs forthcoming.