It will close when Perl hits the semi-colon, because that is when Perl realises the object has gone out of scope.

Quick demo:

use v5.14;

package Foo {
    sub new {
        my $class = shift;
        say "new";
        bless [] => $class;
    }
    sub some_method {
        my $self = shift;
        say "some_method";
        return $self;
    }
    sub other_method {
        my $self = shift;
        say "other_method";
        return 123;
    }
    sub DESTROY {
        my $self = shift;
        say "DESTROY";
    }
}

say "START";
say Foo->new->some_method->other_method and say 456;
say "END";
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DESTROY happens after "456" is printed, but before "END".