It's still different because it would change up the dynamic. De Jong currently has all of the cards, he's done everything right. No matter the outcome he comes out as the good guy (even if Barca will make him out not to be). If he publicly stated he wouldn't mind the challenge of the Premier League, but cannot due to deferred wages, Barca could still turn around and say "So you have publicly said you don't mind moving, but are being greedy. You need to accept a lower fee to move. The fans now expect you to move because you said you don't put Barca ahead of every option".
And not that it's right, but United seem to be treated differrently than the Spanish giants. It's OK if a player is open to leave us, but wanting to leave Barca/Real is a death sentence to your time in the club.