If you actually stopped and took a moment think about how this would actually work in game, you'd realise that it would play *NOTHING* like OG cleric stance from back then because we have so many oGCDs now that completely ignore it.
The suggestion's main failing isn't 'UGH Cleric Stance bad', it's ugh I can just cast it at the start of a mainstream duty and never touch it again once you've got some semblance of talent with your oGCDs. WHM would be the only one actually wanting to do the dance to spend Lilies without eating the fizzle delay. Do you think a SCH, AST or Sadge would have a remotely difficult time healing a current Experto or Alliance without ever touching a healing GCD? (Spoiler, you've pretty much achieved just that on SCH on the very first log I clicked on, a Halone kill if you're curious).
If you actually understood this game to the level that you seem to try to suggest, you'd understand and spot that failing. But you didn't. You just went 'ew cleric stance I didn't like it the first time round, enough said'. No thoughts, head empty.
It's a shame, as frankly I really quite like it as a concept even if it is almost entirely illusionary once you actually get stuck into it.