More importantly, the fact that major libraries are dropping Python 2 support is not meaningless. (Again, I suppose, it's possible that people could fork IPython, NumPy, Django, etc., from the last Py 2 supporting version and extend support, but that seems even less likely than the core language getting solid support by way of a community fork.)
Or the community -- including companies with huge resources and lots of Python 2 code -- will just fork 2.7 and fix it.
Anyone who's every ported a very large project from 2 to 3 might end up despising the PSF for this purpose and might tend to search for a new language (Nim? Go? JS? Scala? Ruby?!). So much for the B in BDFL..
Yeah, but a name like "Cobra, a fork of Python 2.7" will do just as well, and everyone that cares enough will know what it is and where to find it.