Nah. as nice as it sounds since the rework cleric is already very good, strong, desirable in groups even without slow, and several other non healing classes that groups can grab get a slow already to supplement not having a shaman healer (rogue slowing poison, beastmaster, enchanter, bard). Giving purge to cleric really hurts shaman even more.
What they should do is give purge to spellblades as that class needs the most help to being more desirable and useful in groups.
