Nope. Sky lake brought the big power efficiency savings. Kabylake will improve 4K video handling but not much else. It's a very minor upgrade.
there was a decent enough jump in power consumption. it's why the new chips are able to be clocked higher and still fall within the TDP.
but other than that, yeah, Kaby Lake is not a significant improvement over SkyLake. But the minor Performance per watt increase that Skylake brings will help battery life on the M.Bpro