Creating dependency between players for MP management is basically the same thing as the synergy that we had in the party for enmity management before Shadowbringers.
They won't go back to this type of design.

Regarding "Buffs, not dots, seems to be the awnser."
I agree and disagree. I personally think they should diversify healers a bit on this aspect.
I don't know, they could have one healer focus on direct damages, one focus on DoTs, one focus on buffs, and one focus on a DPS resource management or something like that.
As I said in another thread, one of the main issues with healer is that they all have Glare and Dia as filler spells. If you give them all a second dia, it doesn't make anything better IMO.