As noone seem to have pointed already, there's one important module on that subject which is Sub::Name. It should allow you to:

use Sub::Name
foreach (keys %news_sites)
{
  *{$_} = subname "generator_for_$_" => sub {...}
}
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But note that you seem to be missing one more important concept here, which is the concept of closures

foreach my $key (keys %news_sites) {
   *{$key} = sub {
       ...
       # as the $key variable was declared in the outer scope of the s
+ubroutine,
       # if the code reference survives longer than this scope it will
+ retain its
       # value
       warn $key; # this will warn the value used when defining this s
+ub.
   }
}
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