That won't work. How would map know to use $__ instead of the normal result. You'd need a different function. Two such functions already exist: List::MoreUtils's apply and Algorithm::Loops's Filter.

use List::MoreUtils qw( apply );
my @bla = apply { tr/h//d } @arr;

use Algorithm::Loops qw( Filter );
my @bla = Filter { tr/h//d } @arr;
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