Well, sort of. The original contract had an option in it for the EU to order that additional 100m doses, which had a deadline to it. The EU have declined to follow that up. It's not quite Az going to the EU and saying, "do you want to buy any more?"
It does rather add weight to the thought that the EU considers that it has quite enough Az on order already, thank you very much. As I understand it, they are currently committed to pay for all 300m, paying in stages as they are delivered. So might the desired outcome for the EU to be to effectively get a settlement which means they don't need to buy all 300m?
I say freely that this is 100% speculation. But, other than political arse-covering, I can't see what on earth else the EU might aim to get out of this. I get that they are pissed off and that they consider themselves let down, but I don't understand what the objective of their suit is.
Presumably all will come out in due course...