We just completed the 3.2 release, which marks a good time to drop some previously deprecated columns.
Since the column has been marked in ignored_columns, it has been inaccessible to application code since then. There's a tiny risk that this might break a Data Explorer query, but given the nature of the column, the years of disuse, and the fact that such a breakage wouldn't be critical, we accept it.
Ted Johansson