Um, that is not true, and if it was then it is more likely that the memory growth would not happen because $foo would be overwritten each time.

use strict;
if (1) {
  my $foo = "hi";
}
print $foo."\n";

__OUTPUT__
Global symbol "$foo" requires explicit package name at scope.pl line 5
+.
Execution of scope.pl aborted due to compilation errors.
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