I find this quite welcomed, though this is not a new thing since conjurer/white mage did have this back in 1.0 era, although handled differently through the skill called Sacred Prism which lets you AOE any selective spells including Regen too.

Kinda reminds me back in original Aurum Vale dungeon where the air there used to be filled with poisonous fumes that will saps health of anyone entering those fumed areas. This is where Sacred Prism + Regen works where 2 WHM needs to work in tandem to manage duration of buffs always continuous until all party member are out of fumed zones.

While I do wish Sacred Prism making a comeback, SS2 should do I guess.