Windows 8 has almost no corporate adoption, so the interesting data point is 2020 and 7, which is just a bit more than three years away. Migration targets should be somewhere around 2019 (last minute really), but procurement for new machines with Windows 10 builds might start being rolled out in the first half of 2019 with most corps, which is practically just 2 years away. Factor in that the next generation chips still need some time to get to marked and you have a rather narrow gap, especially with corps that have a more conservative hardware policy. I don't see the issue here. I just hope that the Windows 10 rolling update will reduce the enterprise upgrade anxiety.