Yeah, unless it's confirmed by club it's better to be pessimistic so that you won't be pissed off if transfer fails.
*Not directed to you*
at few asking for what proofs anyone have to believe some story or questioning journalists reporting some story, if that's what they believe then they should close all the transfer threads and keep on refreshing ManUtd.com. No player will keep on updating what's going on before the transfer is done, it's usually journalists who either makes up or gets some news from agents/club sources (which they won't name for obvious reasons)