Well, no. Triage healing never worked, ever. Absorbs have nothing to do with that failure. It was an unworkable concept as it was implemented in Cata.
Would you care to expand?
As I understand it, the concept of triage is that you have some high HPS, low HPM heals (eg Flash Heal) to use in "oh !@#$" situations, and some low HPS, high HPM heals (eg Heal) to conserve mana when you can afford to heal people slower, and if you don't know which is which, you're going to blow your mana on overheals/fast heal spam, go OOM, and wipe.
What part of that is unworkable?
The part where the small, cheap heal was a 2.0 second cast, the fast, high cost heal was balanced such that it was never worth casting, and the big, slow heal ended up being the most efficient thing in your toolkit even though it had the same cast time as the small, cheap heal. The result of this was that people stopped using the small, cheap heal very quickly and ended up leaning on the big, slow heal for the majority of the expansion until they got the mana to do spam the expensive heal occasionally in between (hello Serendipity weaving). For Priests and Shaman, in particular, Triage as it was implemented in Cata just never worked. Heal, as a spell, is inefficient and too slow to be worth casting. Flash Heal cost too much, but Greater Heal was extremely efficient so everyone used GHeal. Meanwhile, PoH got buffed to the point that it was actually more efficient to just cast PoH if 2 people took damage and give everyone else shields. On the Shaman front, Tidal Waves propped up Healing Wave for a bit, but I can tell you as someone who mained a Shaman for most of Cata, I stopped casting Healing Wave while I was doing heroics. It simply didn't heal for enough to be worth my time, even when it was fast. I swapped to Tidal Waves-hasted GHW very quickly.
What's more, the idea of Triage was that you could leave some people low for a while or just heal them up very slowly with cheap, low HPS heals. The problem with this is that it never made it to the actual game. Oh, it existed in the normal 5 mans, but by the time you hit Heroics, damage was intense and you couldn't afford to leave someone low because they would inevitably step in something and get one-shot at half-health. In raids it was worse. Was I sucking on fumes for most of the encounters? Yep. Was I still spamming heals because people were going to die otherwise? Yes. There was no way around it.
They tried the Triage model in the raids during Beta, but it was so boring and slow that they scrapped it and put the heavy damage back in.