&BLA; is actually equivalent to BLA(@_);. This works in your case because @_ is empty, but if you use this syntax within a sub, you'll forward its arguments.

use feature 'say';
@_ = qw/4 5 6/;
our $AUTOLOAD;
sub AUTOLOAD { say "Autoload called as $AUTOLOAD(@_)" }


BLA(1,2,3);
&BLA;
__END__
Autoload called as main::BLA(1 2 3)
Autoload called as main::BLA(4 5 6)
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