Somehow I doubt the home button will go away for iPhone 7, but I can't imagine that going forward it will still be a separate physical switch. At most I would expect a depression in the display instead of an actual hole, and 3D touch to give it a clicky feel, just like more recent trackpads.
This might be even cheaper to manufacture, is one less point of failure, and eliminates another area of water entry.
This might be even cheaper to manufacture, is one less point of failure, and eliminates another area of water entry.