Declaring a variable with a post fix conditional is really confusing. If the conditional is false, its not clear if the variable will be false, undefined, undeclared, or what. It’s much more straightforward to make variable declarations separately.

my $foo = $baz if $bar;         #not ok
my $foo = $baz unless $bar              #not ok
our $foo = $baz for @list;              #not ok
local $foo = $baz foreach @list;        #not ok