FWIW,  [ a, b, c ] could also compile to an expression if subroutines  a() b() c() had been defined, but somehow I don't think that's what hennesse was going for.

c:\@Work\Perl\monks>perl -wMstrict -MData::Dump -le
"sub a { return 'foo'; }
 sub b {               }
 sub c { return 'bar'; }
 ;;
 my $array_ref = [ a, b, c ];
 dd $array_ref;
"
["foo", "bar"]
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(Note that  b() intentionally returns an empty list.)