As a shorter version of the above:

* the current install time bundling of setuptools in `ensurepip` is likely to be replaced by `pip` dynamically installing both `setuptools` & `wheel` when asked to build from a source archive when no other build system has been specified. With PEP 517 approved, it's entirely plausible that this will happen as part of the `pip 10.0.0` release. So we *won't* be bundling wheel as part of ensurepip, since doing so would conflict with the plan to unbundle setuptools.

* however, we *may* still end up bundling wheel with CPython at some point, *if* we decide to eliminate Lib/distutils entirely in favour of bundling setuptools & wheel.

So it isn't that bundling wheel is entirely out of the question - it's just not something we want to do as part of ensure*pip* specifically.