It doesn’t matter whether pip switches to installer or not — wheels are installed in the same manner, by installer.
The way scripts in setuptools works is that it dumps the file directly into the scripts scheme. Entry points will dump a wrapper to call the entry point. The main reason to prefer entry points is for cross platform support (as mentioned)
If we want to kill placing raw files in the scripts scheme, we would only be able to do that by breaking backwards compatibility, and one place to do that would be a wheel 2.0 format.