Based on current priority, I suspect that vampirism won’t be changed for a while, but also that when it comes around again, we will continue from where we left off testing last time.
If you see what is in progress here from me: Development Timetable
Those two things are fairly big tasks and if Terraria updates before they are finished, it might also increase the delay further. I imagine at least one of the supporter abilities will be prioritised over this one first.