Interestingly, in all cases, either the block is optional, or there's an alternative, non-block syntax:

map    EXPR,   LIST;
grep   EXPR,   LIST;
print  LIST;   print  BAREWORD LIST; print $HANDLE LIST;
exec   STRING; exec   LIST;
system STRING; system LIST;
[download]

And some you missed, also have a non-block syntax:

sort   BLOCK   LIST;
sort   SUBNAME LIST; sort LIST;
eval   BLOCK;
eval   STRING;
[download]

Not sure whether there's a common issue behind this, or that it's just a coincidence.