Of course, healers and paladins using heal or rejuvenate doesn't work anymore but ways that you can heal outer guardians are:

Herbs
Field dressing
Mass healing (charity paladin/healer)
paladin/healer bandage skill(can't remember exact)
poultice (disease/poison)
lay hands
and maybe more...

Invokers can shield outers
Some paladins and healers can aura them
bards and boost them with songs
mages with talismans

So there are still a lot of things that benefit/heal outer guardians that is still available, it was just the heal supplication, and rejuvenate that was taken away.