No. What I think is that the events at Iuka mean that we cannot necessarily say that (for example) Grant's aggressive tendencies were unaffected by Shiloh.Yet here, with a plan between two columns completely falling apart, with lousy communication between the two columns,... you think one commander should have charged ahead blindly?
It is not an example of a lack of aggression, but it is not really a positive example of aggression either; it is effectively a null data point, which does not indicate a presence of pre-existing aggression.
I should also clarify that it's possible to push forward a recce in force without becoming fully involved, at least to my understanding, or rather that you can arrange matters so that if the enemy does react with their whole force you can take on a defensive alignment.
I am in no sense arguing that Ord should have unilaterally brought on a battle with the whole of the enemy force on the 18th or 19th (though doing so under Grant's orders wouldn't be "unilaterally"). I am arguing that there are cases where Ord's actions indicate he was not taking the "most aggressive available reasonable option", as it were.
Similarly, the plan had initially been for Ord (with two divisions on one road) to open the engagement and Rosecrans (two divisions on two roads, as per the plan) to come in afterwards; Grant changed this to be that Rosecrans should open the engagement and Ord should come in afterwards, but as far as I can tell (and I may well have missed a dispatch from Grant to Rosecrans to that effect) he didn't actually tell Rosecrans that. This could feasibly have resulted in a situation where both columns expected the other to open the fighting first.
Ultimately it's basically a case where the coordination collapses owing to Clausewitz' friction.