1 player per group with 6p Vithu is almost a prerequisite for gauntlet, having a Druid would allow to pass on this so i would not worry too much.
Monk can also heal but not currently used from what i see as well as some paragon skills.
First Vanguard runs requires at least 1 healing charm than can be replaced by 6p vithu or a druid.
This should bring more flexibility.
Otherwise, everybody knows that druid should be nerfed even before it goes live 
but maybe this time, it will not be a DPS/OS issue but a tankiness one.
However, players should not judge a class on its skills/essences partial description. Damage, range and CD values can have significant impact on its effectivness.
Finding druid meta and counters will also take some times (though, 60 essences is not that much to explore). Having 50%+ of player base switching to druid will make things unbalanced for a short time. So, a bit of patience is required ^^