For non-indexed columns ranges are created when optimizer_use_condition_selectivity > 2 and with the help of EITS we are able to make estimates for predicates which involved non-indexed columns.

Eg:

   SELECT * FROM t1 WHERE a = 10;

If there is no index on column a we will create a range for a=10 and get the statistics from EITS. It would be good to print this range in the optimizer trace too.
We already print ranges for indexed columns in the optimizer trace.