Yes interesting.
I know Nems will do this. Or at least BTA Nems. Has 12 or so green BTA’s. All where bleached sadly, the previous owner didn’t have proper light. And was surprised they even lived as long as they did. But got one to green up pretty quick under green lights. The others not so much.
After some days they stated moving and the one that had enough Zooxanthellae and turned green started touching in with the others that had a harder time. And the green started coming back like you wouldn’t believe. I was ready to trim a leg from the one that turned way before the others, to feed little bits to then still bleached gbta’s. But in the end didn’t need to, they transferred it between themselves.
Then I read more about this. And sure for interesting. Poor gbta’s where wrecked. But turned out just fine. A pic from some years ago when this took place.