Maybe none.
I thought it would have an influence, but the correlation is 0.12 between IOD and AO, and -0.16 vs NAO.
Could be a lag effect that I'm missing here. I was excited about the IOD at first yesterday when bluewave talked about the potential effect it had on the 19-20 season, but after digging into the data myself, I just don't see a slam dunk effect by the IOD.