The obvious and overwhelming question is whether the actual world could – or can – accept any sort of major revision to the language. In the last few weeks I have recommended to several clients that they should not move their PHP-5 applications to PHP-7, because of the many arbitrary (and, utterly breaking) changes which the designers of that language made. Their actions imposed, sometimes, "hundreds of thousands of dollars' worth of changes" to the source-code of their systems, simply to keep them doing what they already did. Having unwittingly pushed a few clients through this, I cannot in good faith do it again. "The right thing to do," in my view, is to insulate themselves from future OS-package-imposed changes and to thereby remain exactly where they are now, for the foreseeable future.
The architecture of Perl, vis-a-vis PHP, is of course very different because most of the features upon which production applications rely aren't "part of the language." Instead, they exist as separate source code ... now, tens of thousands of lines of it. Therefore, the single overwhelming concern for any "Perl user," when now faced with "Perl+=2," is not that "the new language is better," but that "100% of my existing source-code continues to run."
The Perl-6 idiots never understood this. Which is precisely why their language went nowhere.