I think he knows that he has enough votes to continue being the spoiler in Wis. He will allocate elsewhere.
Kasich has an endless supply of Soros backing $. Looking at the polls in WI he is doing well enough without spending on additional ads. He might finish ahead of the GOPe wonder boy Cruz in WI which would not be a good look for the Bushes, Romney, Rove, etc. I’m guessing he was told to pull the ads by the GOPe and like a good soldier Kasich obeys.