By definition, giving a player the ability to veto a trade makes it more difficult to trade him.
That single aspect makes it more difficult to trade him. However his contract was always prohibitive. Now it's not.
Now he has a veto yes, but now team are actually would be willing to trade for him.
I'd say it's a net improvement to trade him
Now does it make sense that they've waited till the first week of September to try to trade him? Probably not, so it's certainly possible they won't be trading him