"Yes, I realize this, but didn't (almost) all Naval Vessels of the time carry scout/recce aircraft? Couldn't they simply grab some binoculars and get a visible conirmation?"
Actually, according to "Sea of Thunder" (an excellent book itself, by the way - I got it for Christmas and picked it up yesterday but I've already devoured my way through 3/4ths of the book!) Kurita was ordered by Japanese High Command to detach a huge number of his float planes (I don't remember how many, but the vast majority) to support land based operations. I presume, although I don't know, more would have been wrecked in the giant US air strike the day before.
You also have to realize that, at least according to the aforementioned book, which offers a fairly complex profile of Kurita and his history along with that of several other officers involved, Kurita wasn't big on the operation to begin with. He was one of the few Japanese naval officers who realized the war was a lost cause at this point and didn't like throwing away the young men under his command in suicidal attacks with no chance of victory. If you think about it, even if he had pressed the attack it was unlikely he would have scored much of a success in broader terms, just killed more sailors aboard the Taffys, transports, and (perhaps) his own ships. A few Jeep carriers were hardly a critical part of the war effort as they were easily replacable, and IIRC the transports and even ammunition carriers had almost all been unloaded - in fact the Japanese admirals scoffed at being assigned to attack them instead of the main American fleet, and thought them an unworthy and useless target. Merchant shipping was something the Americans could produce en masse and sinking empty transports would barely have delayed the American campaign.