God is omniscient and knows the future. There is nothing to know that God doesn't know. In other words, He is not an ignorant God.
The idea that God could "choose not to know" is one of the more bizarre of the Watchtower teachings. First He would have to decide what it was it was He didn't want to know, then He gives Himself a bout of amnesia. It makes no sense whatsoever.
I've seen some of the objections on this board, and I have few moments, so I'll discuss some of them. Please feel free to respond. I'll try to get back as soon as possible but you may have to be patient at times.
Let's discuss Nineveh first. Did God make a mistake by pronouncing judgment on Nineveh? Not at all!
"...
Yet 40 days and Nineveh will be overthrown." (Jonah 3:4)
"
When God saw what they did and how they turned from their evil ways, he relented and did not bring on them the destruction he had threatened. (Jonah 3:10)
Contradiction? Proof that God doesn't know what on earth (or heaven) He's going to do? Not exactly...prior to the announcement against Nineveh, God specifically stated: "
If that nation, against whom I have pronounced, turn from their evil, I will repent of the evil that I thought to do unto them." (Jeremiah 18:8)
Nineveh repented, and God did exactly as He stated He would do.
Secondly, let's look at Jonah 3:4. The hebrew word "haphak" is used here. Haphak can mean overthrown, but it also means to convert or change:
הָפַךְ hâphak, haw-fak'; a primitive root; to turn about or over; by implication, to change, overturn, return, pervert:—× become, change, come, be converted, give, make (a bed), overthrow (-turn), perverse, retire, tumble, turn (again, aside, back, to the contrary, every way).
That's exactly what happened in Nineveh...they responded to Jonah's message, and much to Jonah's chagrin, they changed.
God's pronouncement was upheld, just as He stated.