I don't think anyone that writes regex would feel specially challenged by using the Alt+ | Ctrl+Shift+u key combos for unicode entry. Having to escape less things in a pattern would be nice.
(“But backtick is annoying to type” said the Europeans.)
I would also imagine that, if this became the norm, IDEs would quickly standardize around common notation - probably actually based on existing regex symbols and escapes - to quickly input that, similar to TeX-like notation for inputting math. So if you're inside a regex literal, you'd type, say, \A, and the editor itself would automatically replace it with the Unicode sigil for beginning-of-string.
Certainly making the perlre library available separate to perl encouraged its widespread use, and lots of others copied or were inspired by it.
"Popularized" doesn't seem like quite the right word though, I don't disagree with the point, but if I shout "Hey everyone let's write regex's" at the office people throw stationary at me, which is not true of other popular things!
I took a look at Raku, which claims be a better Perl maybe, or closely related but more modern, it certainly looks nice. Although i am a big fan of typed languages, Raku piqued my interest.
my Int $a = 42; # ok
my Int $a = "foo"; # Type check failed in assignment to $a; expected Int but got Str ("foo")