It’s somewhat bikeshedding so it’s up to you 
I would say though that we enforce compliance with those other PEPs by saying that if you don’t follow those PEPs, then your thing is unlikely to continue to work. Like we can’t force people to format their versions correctly, but if they don’t then it’s unlikely a large set of tools will function.
This is inherently different, since it’s not saying that virtual environments are the only way to install something, it’s just changing the defaults, the UX of installers, and in the past we’ve gone to lengths not to dictate what UX the various tools provide.