Planarize tool needs the template functionality.

[-_Ashley-B-Potter_-]

The planarize tool does not hold to the current symbology of the lines selected (subtype). It defaults to the "default line subtype". It also does not update COGO attributes or holds the current COGO attribute data, if applicable. You may have cases where some lines are COGO and some are not. When everything defaults to the default symbology and not the symbology of the line symbology you drew with. it can lead to confusion to what to keep. Having the template option could help mitigate this issue. 

added update COGO option too.