That can be achieved right now for anyone who is interested: download Perl5.32 and never update it. No one will ever force you to upgrade to Perl7 if you don't want to. Why hold everyone else back when remaining in a static state can be done in isolation?
I think this is an interesting sentiment when contrasted with the Python 2/3 split, where most people are pushing to get projects into on 3 and warning users of 2 they will not be getting official security patches any more. Maybe because Perl's community is smaller they wouldn't be as hard-line on this and release security fixes for Perl 5 if they were merited (though I don't see Perl as a tempting target for malware authors).
It feels like that article states that some people in the Perl community want to make the breaking changes to free themselves of legacy and gain the advantage of accessibility from new users by doing so, being that Perl 5 desperately needs new users, but contrasts this with the fact that protecting that legacy was both a core value of the Perl project and possibly one that held it back for too long.
I honestly wonder where we would be if Python never made the 2/3 split and we'd all still be using Python 2 at this point with all of its design flaws. Surely it wouldn't die from becoming outdated, seeing other languages do the same things better, as with Perl?