It's very likely to!
This is pure speculating, but if I take this qualified example: The cask strength Highland Park 12yo was 55% before watered down and the 18yo was 52% before being watered down. This is totally made up by me, but I reckon it's a very realisitic example. In reality the ABV could have been different, similar and (unlikely though) higher for the 18yo.
But with these examples (I will spare you for the math): For every liter of whisky in the bottles approx. 27cl is added water for the 12yo and approx. 17cl is added water for the 18yo. Quite a lot, actually, in both examples, but also a remarkable difference.
One thumb rule is that alcoholpercentage goes down in the cask as the whisky matures (true for Scotland). Older whisky is weaker than younger whisky. Older watered down 40% whisky have less water added than a younger watered down 40% whisky!
Here is my opinion of the whisky
4. Highland Park 18yo 43%
The flavour profile of this is not far from yesterdays dram. But what you get is a more oily experience. Logical, as there should be less added water. As there is less water added, the concentration of "flavour molecules" is higher, The sherry is slightly more dominant. I pick up minty flavours as well. I get around the same amount of peatyness as in the 12yo. Again a well balanced sherry peaty whisky, and not as sweet as the 12yo- A great dram
Peatin' malt in 2007 at Highland Park
Off course its not just the ABV and added water that matters. Extra 6 years in cask and a different selection of cask types is also part of what makes this whisky what it is