I appreciate the logic, but I think you're treating Madrid too much like a normal football club. A normal football club doesn't replace one of their better players for no reason. Heck, a normal football club doesn't buy Gareth Bale for £85m.
The clauses are misleading too, I imagine a massive proportion of that would be CL win dependent, something Di Maria has not achieved at Madrid.
Regardless, from both the player and the clubs point of view it might make sense to let Di Maria go if Bale signed. From the players perspective he'd probably go from being first choice to behind Ronaldo, Bale, Isco and Ozil in the pecking order through no fault of his own and you'd have to imagine (given the fees paid for them) that they'd not be much rotation of Ronaldo and Bale. I could completely understand him wanting to leave if that transfer went through.
From Real Madrid's perspective he's on €3m a a year and he's barely needed in this scenario, €25m might be a loss on his initial transfer but it would mitigate the cost of some of the Bale transfer and his wages.
I can completely see where people that disagree with that argument come from, but I find it hard to believe that the scenario that would leave Di Maria leaving Madrid this year could see Madrid demanding a high fee.
if true