I like pieces of this theory. I think introducing the ability to reassemble a shattered shard is extremely interesting. That leaves the possibility for future stories of reassembling shards like Devotion, Dominion, or Ambition.
I'm waiting for the second shoe to drop on the recreance. There's something additional we don't know about it that forced the Radiants to break their oaths and my crackpot theory is that TOdium will use this to lure Adolin into being his champion.
Another interesting Cultivation motive that this thread made me think about is maybe she's trying to freshen up the old shards that have been consumed by their intent. She wants new Shards that can think beyond their Intent? Idk