@Jezebel -

The link you provided is about the Mana Stream totem going Raid wide and not stacking. Someone here mentioned earlier that Healing Stream will be going raid wide. We're trying to find information related to that fact...

To quote Blue on your link,

We are making a change to these spells so that their benefits are exclusive in patch 3.1.0. The buffs will be equivalent, but will no longer stack. Mana Spring will affect the entire raid instead of just the shaman’s party. We felt that both paladins and shamans brought too many unique buffs to a group. Additionally, we have been trying to tone down mana regeneration in large groups, and were concerned raids would feel the need to stack paladins or especially shaman to have enough Mana Spring totems. We have also been trying to get more benefits out of the party and into the raid, and Mana Spring previously was still a party only buff. With this change, if there is only one paladin, he or she can bring Blessing of Kings while the shaman offers Mana Spring. If there are two paladins and the second offers Blessing of Wisdom, then the shaman can offer healing or cleansing with their water totem instead.
Blue post -> "these spells" referring to Blessing of Wisdom and the Mana Spring totem.

This change affects mana stream only. There is no mention of healing stream in this post.