HoTs are buffs and yes you now need to monitor them, this aligns with how Custom Debuffs work.
There is no overhead in turning on monitor for buffs, within the code, checking for buffs and hots are within the same function sharing the appropriate API calls.
I should add and for the benefit of others who come across this.
Another reason for using the Monitor for Buffs option is due to Custom Buffs can now change the bar colour and it is now possible to change the bar colour and not show an icon, Custom Debuffs have worked this way for a long time.
I've now installed 8.2 and I still can't see any icons on my resto druid. They show up for my holy priest, mistweaving monk, and resto shammy... but not my druid.... I've completely deleted healbot from the wow folder, cleared my cache, and reinstalled with no change. It's only icons on my druid. I can't see any HoT's/absorb icons on my bars....
Help? Not sure what else to do...
GAH! I didn't see the last post on this page... monitor buffs on.. icons show... good grief.. thank you! /facepalm